# Questions on Algebra: Probability and statistics answered by real tutors!

Algebra ->  Probability-and-statistics -> Questions on Algebra: Probability and statistics answered by real tutors!      Log On

 Ad: Algebrator™ solves your algebra problems and provides step-by-step explanations! Ad: Mathway solves algebra homework problems with step-by-step help!

 Algebra: Probability and statistics Solvers Lessons Answers archive Quiz In Depth

 Question 204720: a) Suppose that in a two-tail hypothesis test you compute the value of the test statistic Z as -1.38. What is the p-value? b) In the above problem, what is your statistical decision if you test the null hypothesis at the 0.01 level of significance? Click here to see answer by stanbon(60771)

 Question 204752: An article in The Wall Street journal implies that more than half of all Americans would prefer being given \$100 rather than a day off from work. This statement is based on a survey conducted by American Express Incentive Services, in which 593 of 1,040 respondents indicated that they would rather have the \$100 )Carlos Tejada, “ Work Week,” The Wall Street Journal, July 25, 2000, A1). a. At the 0.05 level of significance, is there evidence based on the survey data that more than half of all Americans would rather have \$100 than a day off of work? b. Compute the p-value and interpret its meaning. Click here to see answer by stanbon(60771)

 Question 204750: Take a coin and flip it 20 times. How many times did you get heads? HOw many times did you get tails? What is the experimental probability that the next time you flip the coin, it will be heads? Click here to see answer by stanbon(60771)

 Question 204748: Investors do not invest all their money in the investment predicted to be the best because it is too risky. An investor holds shares in three independent companies:Company A, Company B, and Company C. An analyst predicts the probability of profit increase for each as follows: Company A:0.70 Company B:0.50 Company C:0.065 A.)If the analyst's predictions are true, what is the probability that all three companies show a profit increase? B.)If the analyst's predicitions are true, what is the probability that at least one company will show profit increase? Click here to see answer by stanbon(60771)

 Question 204746: One particular high school encourages students to donate blood. The high school gym is set up for this purpose. The distribution of blood types in North America is as follows: Type O: 44% Type A: 42% Type B: 10% Type AB: 4% A.) What is the probability that the first two people in the line up have the same type of blood?? B.) What is the probability that none of the first five people in the line have type AB blood?? (Express all answers in nearest hundreth of one percent) Click here to see answer by stanbon(60771)

 Question 204791: in a certain state, a survey of 500 workers showed that 45% belonged to a union. Find 90% confidence interval of the true proportion of workers who belonged to a union. Click here to see answer by stanbon(60771)

 Question 204774: ) In how many ways can 6 instructors be assigned to six sections of a course in mathematics? Click here to see answer by stanbon(60771)

 Question 204804: The odds against Thunderbolt winning the Birmingham Derby are 11:3. Find the probability that Thunderbolt wins. A) 3/11 B) 3/14 C) 8/11 D) 8/14 E) 3/8 Click here to see answer by stanbon(60771)

 Question 204803: A license plate is to consist of three letters followed by two digits. How many different license plates are possible if the first letter must be a vowel (a, e, i, o, u), and repetition of letters is not permitted, but repetition of digits is permitted? Click here to see answer by stanbon(60771)

 Question 204807: Two cards are drawn without replacement from an ordinary deck of 52 playing cards. What is the probability that both are spades if the first card drawn was a spade? I got so far that there are 13/52 and then you take away one giving you 12/52 and then I am lost. Click here to see answer by stanbon(60771)
 Question 204807: Two cards are drawn without replacement from an ordinary deck of 52 playing cards. What is the probability that both are spades if the first card drawn was a spade? I got so far that there are 13/52 and then you take away one giving you 12/52 and then I am lost. Click here to see answer by gerrylucas(2)
 Question 204807: Two cards are drawn without replacement from an ordinary deck of 52 playing cards. What is the probability that both are spades if the first card drawn was a spade? I got so far that there are 13/52 and then you take away one giving you 12/52 and then I am lost. Click here to see answer by edjones(7794)

 Question 204802: How many different ways are there for an admissions officer to select a group of 6 college candidates from a group of 15 applicants for an interview? Click here to see answer by stanbon(60771)

 Question 204809: A box contains two black balls and three gold balls. Two balls are randomly drawn in succession from the box. a. If there is no replacement, what is the probability that both balls are black? b. If there is replacement before the second draw, what is the probability that both balls are black? I am having a hard time putting these into formulas. The answers I got are a. 2/3 and b. 2/5 Click here to see answer by gerrylucas(2)
 Question 204809: A box contains two black balls and three gold balls. Two balls are randomly drawn in succession from the box. a. If there is no replacement, what is the probability that both balls are black? b. If there is replacement before the second draw, what is the probability that both balls are black? I am having a hard time putting these into formulas. The answers I got are a. 2/3 and b. 2/5 Click here to see answer by stanbon(60771)

 Question 204800: At an annual flower show, 7 different entries are to be arranged in a row. a) How many different arrangements of the entries are possible? b) If the owners of the 1st, 2nd, and 3rd place entries will be awarded prizes of \$100, \$50, and \$25 respectively, how many ways can the prizes be awarded? Click here to see answer by edjones(7794)

 Question 204812: To bid competitively for the lumbering rights on a certain tract of land, a wood product firm needs to know the mean of the diameter of the trees on the tract to within 2 inches, with a probability of .90. How large a sample of trees should be selected from the tract to estimate the mean diameter if it is known that the diameter of the usable timber on the tract ranges from 10 to 38 inches. Click here to see answer by stanbon(60771)

 Question 204718: The diameter of Ping-Pong balls manufactured at a large factory is expected to be approximately normally distributed with a mean of 1.30 inches and a standard deviation of 0.04 inches. What is the probability that a randomly selected Ping-Pong ball will have a diameter of: a. Between 1.28 and 1.30 inches? b. Between 1.31 and 1.33 inches? c. Between what two values will 60% of the Ping-Pong balls fall (in terms of the diameter)? If random samples of 16 Ping-Pong balls were selected, d. What proportion of the sample means would be between 1.31 and 1.33 inches? If random samples of 100 Ping-Pong balls were selected, e. What proportion of the sample means would be between 1.31 and 1.33 inches? f. Compare your results in (b), (d) and (e). Click here to see answer by stanbon(60771)

 Question 204881: As a part of the survey of the UK financial services market, a sample of 100 bank customers was selected. Each person was asked to indicate the degree of confidence they felt about their bank, using the categories in the table shown below. The table shows how each response was converted to a numeric scale: The score 5 stands for VERY HIGH, 4 for HIGH, 3 for MODERATE, 2 for LOW and 1 for VERY LOW SCORE - Number of Customers 1--- 11 2--- 27 3--- 35 4--- 19 5--- 8 Total--- 100 Conduct a descriptive analysis of this data: fully explain the reasoning involved in any measures you have chosen and consider possible problems with the data. (I have no clue how to figure out a grouped data question from a direct ungrouped question for measures of centrel tendency, unless the confidence intervals are directly given) For instance, I could not identify the above question is a grouped data question, found the mean, median, mode direct and lost marks. Kindly guide me to the accurate way of solving such questions please. Click here to see answer by stanbon(60771)

 Question 204904: A specific brand of bike comes in two frames, for males or females. Each frame comes in a choice of three colors, red, white, and blue, and with a choice of three seats, soft, medium, and hard. a) Use the counting principle to determine the number of different arrangements of bicycles that are possible. b) Construct a tree diagram illustrating all the different arrangements of bicycles that are possible. c) List the sample space. I have been working on this question for about 2 days now and I seriously do not know how to do a tree. Well I know how to make one I think but I don't know where to begin.. Please someone help if you have the time.. This is the last question on my assignment. Please help... Click here to see answer by jim_thompson5910(29613)

 Question 204895: The total amount being spent on personal calls in a month by employees of a company follows a normal distribution with a mean of \$900 and a standard deviation of . Find the probability that in a randomly selected month the amount spent on personal calls is less than \$750. A) 0.8333 B) 0.0013 C) 0.1667 D) 0.9987 i just need some ideas and tools to solve this one. i am so bad a t standard deviation! please!!! thankyou more than you know!!! Click here to see answer by stanbon(60771)

 Question 204892: Two cards are drawn without replacement from an ordinary deck of 52 playing cards. What are the odds in favor of drawing two queens? I am confused by this... i would assume it to be 4 out of 42 because there are 4 queens n a deck of 52, but my options are A) 1:220 B)1:168 C) 1:221 D)220:1 Click here to see answer by alicealc(281)

 Question 204894: A machine has four components, A, B, C, and D, set up in such a manner that all four parts must work for the machine to work properly. Assume the probability of one part working does not depend on the functionality of any of the other parts. Also assume that the probabilities of the individual parts working are P(A) = P(B) = 0.93, P(C) = 0.95, and P(D) = 0.92. Find the probability that the machine works properly. A) 0.8128 B) 0.2441 C) 0.8217 D) 0.7559 I dont even know what route to take or where to start on this one..please help at least point me in the right direction! Click here to see answer by alicealc(281)

 Question 204907: Please help w/ the following: A box of chocolates contains 20 identically shaped chocolates. Four of them are filled with jelly, seven are filled with caramel, and nine are filled with nuts. What is the probability that one chocolate chosen at random is filled with caramel or nuts? P(selecting a caramel or nut chocolate) = 16/20 = 4/5 P(failure to select a caramel or nut chocolate) = 4/20 = 1/5 Odds against picking a caramel or nut chocolate = (1/5)/(4/5) = 1/5 x 5/4 = 1/4 = 1 : 4 Odds in favor = P(success) / P(failure) = (4/5)/(1/5) = 4/5 x 5/1 = 4/1 = 4 : 1 Click here to see answer by stanbon(60771)

 Question 204953: The total amount being spent on personal calls in a month by employees of a company follows a normal distribution with a mean of \$900 and a standard deviation of \$50 . Find the probability that in a randomly selected month the amount spent on personal calls is less than \$750 i cant seem to figure this out or even know where to begin!... i would be so,so,so greatful if someone would point me in the right direction and at least give me some tools!please! Click here to see answer by stanbon(60771)

 Question 204952: The tread life of a particular brand of tire is a random variable best described by a normal distribution with a mean of 60,000 miles and a standard deviation of 1600 miles. What is the probability a randomly selected tire of this brand will last between 56,640 miles and 57,120 miles? i cant seem to figure this out or even know where to begin!... i would be so,so,so greatful if someone would point me in the right direction and at least give me some tools!please! Click here to see answer by stanbon(60771)

 Question 204966: Half of the scores in any data set are below the A) first quartile B) midrange C) third quartile D) median E) fourth quartile Click here to see answer by RAY100(1637)

 Question 204965: ) The number that appears most frequently in a data set is the A) mean B) midrange C) median D) mode E) average Click here to see answer by RAY100(1637)

 Question 204962: Three-fourths of the numbers in any data set will be larger than the A) first quartile B) third quartile C) median D) midrange E) fourth quartile Click here to see answer by RAY100(1637)

 Question 204955: I am having trouble with this: 500 tickets for prizes are sold for \$2 each. Five prizes will be awarded - one for \$300, one for \$200, and three for \$50. Steven purchases one fo the tickets. a)Find the expected value. b)Find the fair price of the ticket. So far, for a, I think you would do something like this: 1st prize: 1/500 = 0.002 2nd prize: 1/500 = 0.002 3rd prize: 3/500 = 0.006 so, \$300(0.002) + \$200(0.002) + \$50(0.006) = \$1.30 For b, I do not know where to begin. Click here to see answer by jim_thompson5910(29613)
 Question 204955: I am having trouble with this: 500 tickets for prizes are sold for \$2 each. Five prizes will be awarded - one for \$300, one for \$200, and three for \$50. Steven purchases one fo the tickets. a)Find the expected value. b)Find the fair price of the ticket. So far, for a, I think you would do something like this: 1st prize: 1/500 = 0.002 2nd prize: 1/500 = 0.002 3rd prize: 3/500 = 0.006 so, \$300(0.002) + \$200(0.002) + \$50(0.006) = \$1.30 For b, I do not know where to begin. Click here to see answer by stanbon(60771)

 Question 204996: The total amount being spent on personal calls in a month by employees of a company follows a normal distribution with a mean of \$900 and a standard deviation of \$50. Find the probability that in a randomly selected month the amount spent on personal calls is less than \$750. i already submitted this but i need to find a way to work through this without a graphing calculator- its not required for the class but the tutor that helped me(Godbless him or her) gave me a solution using a calculator. does anyone now how to do this without one? please help me!!! Click here to see answer by stanbon(60771)

 Question 205048: An=5 D=-2 N=12...............Find the sum of the arithmetic sequence having the data given and explain how to solve it please Click here to see answer by stanbon(60771)

 Question 205063: The odds against Lightning winning the third race are 9:4. If Sally places an \$8 bet on Lightning to win and Lightning wins, find Sally’s net winnings.. I know that is equals 18 but I don not know how to to the figures on it can some one please help me.. My aunt helped me but she didnt explain how to get the answer.. please help Click here to see answer by rfer(13569)

 Question 205128: The following statistics provide information about the scores on a national History exam. Mean 540 First Quartile 260 Median 450 Third Quartile 678 Mode 468 90th Percentile 890 a) What score did half of the test takers surpass? b) What was the most common score? c) What percentage of the test takers scored 678 or better? d) If Joe had a score of 890, explain the meaning of his score. Click here to see answer by rfer(13569)

 Question 205126: State True or False a) A collection of all the objects to be studied is a population. b) A subset or part of the population is called a partial population. c) In a frequency distribution, the class size is always 4. d) The sum of the percents of the sectors in a pie chart should be 100%. e) A frequency distribution can be illustrated using a histogram. Click here to see answer by stanbon(60771)

 Question 205125: Construct a histogram and a frequency polygon for the following frequency distribution Miles class 0 - 20 21 - 40 41 - 60 61 - 80 81 –100 Number of Commuters Frequency 7 3 12 10 4 Click here to see answer by stanbon(60771)

 Question 205286: Two cards are drawn without replacement from an ordinary deck of 52 playing cards. What are the odds in favor of drawing two queens Click here to see answer by Alan3354(34674)

 Question 205041: I am so stuck on these 4 questions. I have read and read and still don't get them. Any help is appreciated. Thank you so much. 1. A machine produces 3-inch nails. A sample of 12 nails was selected and the lengths determined. The results are as follows: 2.89 2.95 3.00 3.05 2.99 2.96 3.10 3.06 3.00 3.12 3.00 2.95 Use these results to test H0:  = 3 and Ha:   3 at  = 0.05. Give the critical region, the computed test statistic, and the conclusion 2. A random sample of 46 observations was selected from a normally distributed population. The sample mean was = 81, and the sample variance was s2 = 35.0. Does the sample show sufficient reason to conclude that the population standard deviation is not equal to 7 at the 0.05 level of significance? Use the p-value method. 3. An insurance company states that 75% of its claims are settled within 5 weeks. A consumer group selected a random sample of 50 of the company’s claims and found 35 of the claims were settled within 5 weeks. Is there enough evidence to support the consumer group’s claim that fewer than 75% of the claims were settled within 5 weeks? Test using the traditional approach with  = 0.05. 4. A machine produces 9 inch latex gloves. A sample of 80 gloves is selected, and it is found that 20 are shorter than they should be. Find the 99% confidence interval on the proportion of all such gloves that are shorter than 9 inches Click here to see answer by stanbon(60771)

 Question 205037: I was wondering if anyone can help me with these. I'm having issues with understanding how they are suppose to go and be worked. The third * I have how I think it should be set up but still don't know how to go any further. Any help is greatly appreciated. Thank you. *The pulse rates below were recorded over a 30-second time period, both before and after a physical fitness regimen. The data is shown below for 8 randomly selected participants. Is there sufficient evidence to conclude that a significant amount of improvement took place? Assume pulse rates are normally distributed. Test using  = 0.05. Before 31 25 30 31 33 25 32 45 After 32 29 30 37 40 35 34 52 * A teacher wishes to compare two different groups of students with respect to their mean time to complete a standardized test. The time required is determined for each group. The data summary is given below. Test the claim at = 0.05, that there is no difference in variance. Give the critical region, test statistic value, and conclusion for the F test. n1=60, s1=24 n2=120, s2=28 = 0.05 *Determine the p-value for each of the following hypothesis-testing situations: a. H0: p = 0.30 and Ha: p  0.30; z test value = 1.65 p(z>1.65) = , p(z<-1.65= b. H0:   30 and Ha:  < 30; t test value = - 1.7 d.f. = 15 p(t<-1.7)= Click here to see answer by stanbon(60771)

 Question 205323: a student council has 5 seniors, 4 juniors,3sophmores, and 2 freshman as members. In how many was can a 4 member council commite be formed that includes one member of each class? Click here to see answer by stanbon(60771)

 Question 205375: Sometimes stores offen incredibly good prices on a product to encourage people to shop at the store. The store usually carries only a few items at the discount price and does not give out rain checks. A new shipment of 9 VCRs, which will be offered at a very low price, are delivered. Unknown to manager, 4 of the VCRs are defective. Determine the probability that at least one of the three VCRs sold is defective? Click here to see answer by stanbon(60771)

 Question 205374: To use telephone banking to paybills,the customerhas to enter the last three digits of each bill. The numbers 0 to 9 inclusive can be used. If the numbers happen to be the same on more then one bill, the costumer has to enter the first 3 digits as well. A.) What is the probability that a person has 2 bills to register with the same last 3 digits? B.)What is the probability that a person with 10 bills to register has at least 2 bills with the same last 3 digits? Click here to see answer by stanbon(60771)

 Question 205406: If four cards are chosen at random from a standard deck of playing cards, how many different ways are there to draw the four cards if at least three cards are a jack, queen or a king? Click here to see answer by stanbon(60771)