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

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 Question 310778: using the letters from the word equation, how many 5 letter patterns can be formed in which q is followed immediately by u? Click here to see answer by stanbon(60771)

 Question 310824: Hi, I really need help on my statistics final, the question is pretty long: For my final I created a survey with the question: Is there a gender preference for fries or onion rings? My null and alternate hypotheses are: HO: There is not a gender preference for either fries or onion rings. HA: There is a gender preference for either fries or onion rings. I've collected the data, and now I need to perform a hypothesis test and I just don't know which one to do. Do I do two seperate two proportion z-tests? And if so, how would I represent that data? I'm sorry for such a long question, and I would truly appreciate any help that you can give me. Click here to see answer by stanbon(60771)

 Question 310836: 6. Given a level of confidence of 95% and a population standard deviation of 8, what other information is necessary: (A) To find the Maximum Error of Estimate (E)? (B) To find the sample size (n)? (C) Given the above confidence level and population standard deviation, find the Maximum Error of Estimate (E) if n = 45. Show all your calculations. Show all work. (D) For this same sample of n = 45, what is the width of the confidence interval around the population mean? Show all work. (E) Given this same confidence level and standard deviation, find n if E = 2.5. (Always round to the nearest whole person.) Show all work. Click here to see answer by stanbon(60771)

 Question 310744: A professor at a local university noted that the grades of her students were normally distributed with a mean of 73 and a standard deviation of 11. If 69.5 percent of the students received grades of C or better, what is the minimum score of those students who received grades of C or better? Click here to see answer by stanbon(60771)

 Question 310857: if a single letter is drawn from the set{m,a,t,h,e,i,c,s}what is the probability that the letter drawn is a member of the set {m,a,t,h}? Click here to see answer by nyc_function(2741)

 Question 310880: A bag contains 7 black checkers and 3 red checkers. once a checker is picked it is not replaced. what is the probability of picking 2 red checkers? Click here to see answer by Fombitz(13828)

 Question 310950: randomly selects answers to all 10 questions on a multiple-choice quiz. Each question has 1 correct answer and 3 incorrect answers. Find the probability that at most 3 answers are correct. Round your decimal to the nearest 1000th. Click here to see answer by stanbon(60771)

 Question 311028: Suppose that the average number of years to graduate at a university is 4 years, with a standard deviation of 0.5 years. Assume a bell-shaped distribution for years to graduate. From the Empirical Rule, what is a range of values that 95% of the students should graduate between? From the Empirical Rule, what is a range of values that 68% of the students should graduate between? From the Empirical Rule, what is a range of values that 99.7% of the students should graduate between? Suppose that the average height for college men is 66 inches. If the height distribution is bell-shaped, and 95% of the men have heights between 60 inches and 72 inches, what is the standard deviation of heights for this population? I know I am repeating but I am so confused! Click here to see answer by stanbon(60771)

 Question 311009: Hi, I was asked to develop a numerical and verbal hypothesis statement and I have but cannot work it. Can someone help me? Here is the hypothesis statement. 1. as part of a study of blue collard citizens, the Director of Human Resources for Whitner Autoplex Car Sales wants to compare the amount of older blue collard citizens purchasing expensive vehicles from Whitner Autoplex, verses those younger in age, purchasing inexpensive vehicles. A sample of 17 citizens over the age of 50 purchased expensive vehicles, with the mean being 35.925 and with the standard deviation of 80 vehicles sold per month. A sample of 64 citizens under the age of 50 purchased inexpensive vehicles, with the mean being 15.546 and the standard deviation of 70 vehicles sold per month. At the .05 significance level, is there a difference in the mean number of older citizens, verses the younger citizens, purchasing vehicles at a high rate? The company will use the five-step hypothesis procedure to show the general manager the outcome of sales. Click here to see answer by stanbon(60771)

 Question 310959: what is the anser for the following, 60% of the students in the computer course passed the test. if 25 students were randomly chosen at random. 1) what is the probabiliy that more than 18 students passed the test 2)what is the probability between 10 and 17 passed the test 3) calculate the expected mean 4)calculate the standard deviation a soft drind bottling company wants to fill bottles labeled 360 ml such that bottles that contain less than 355.5 ml will be declared as non-quality standard and sold st substantial discont. the fills are normally distributed with a mean of 360 ml and standard deviation of 3.50ml. if 20,000 bottles are filled, approximatly HOW MANY will be declared as non-quality standard Click here to see answer by stanbon(60771)

 Question 311187: A card is drawn at random from a standard deck of cards. Find each probability. P(King or Queen) P(Ace or Club) P(2,3,4,or spade) Thankyou. Click here to see answer by checkley77(12569)

 Question 311193: There are ten boys and twelve girls in the Leadership class. The homecoming committee has 4 members that will be picked from the lead class. What is the probability that the homecoming committee will have at least three girls? Thankyou. Click here to see answer by Edwin McCravy(9717)

 Question 311203: Hello, this is the problem Im having currently, I have no idea were to start. Problem: Of 30 microwave ovens 6 are defective. what is the probability that exactly 2 of the first 4 microwave ovens are defective? Thanks so much! Click here to see answer by scott8148(6628)

 Question 311279: an electronics company produces a headphone set that can be adjusted to accomodate different sized heads. research into the the distance between the top of peoples heads and the top of their ears produced the following data in inches: 4.5, 4.8, 6.2, 5.5, 5.6, 5.4, 5.8, 6.0, 5.8, 6.2, 4.6, 5.0, 5.4, 5.8 the company decides to design t heir headphones to acoomodate three standard deviations from the mean. find, to the nearest tenth, the mean, standard deviation, and the ranged that must be accomodated. Click here to see answer by Fombitz(13828)

 Question 311278: a set of normally distributed student test scores has a mean of 80 and a standard deviation of 4. determine the probability that a random selected score will be between 74 and 82. Click here to see answer by Fombitz(13828)

 Question 311232: The distribution below is not a probability distribution for which of the following reasons: X 0 1 2 3 4 P(X) – 0.5 0.1 0.3 1.2 .02 a)  P(X)  1 c) P(3) > 1 e) all of the above b) P(0) < 0 d) b and c only I thought this answer was a but it was wrong can you explain why Click here to see answer by Fombitz(13828)

 Question 311233: Find the mean of the following probability distribution: X 0 5 10 15 P(X) 0.3 0 0.2 0.5 a) 0 c) 30 b) 9.5 d) 1 i thought the answer was c but it was wrong can you explain it to me Click here to see answer by Fombitz(13828)

 Question 311230: You are generating pin codes for ATM cards. Each pin code has 5 places, and each place can be a small letter or a number between 0 and 9. No letter or number can be used more than once. How many different codes are there? a) _10_ * _9_ * _8_ * _26_ * _25_ c) 26! + 10! b) _36_ * _35_ * _34_ * _33_ * _32_ d) _35_ * _34_ * _33_ * _32_ * _31_ I thought the answer was d but i got it wrong can you explain why? Click here to see answer by Fombitz(13828)

 Question 311285: X P(x) -1 .25 0 .15 1 .10 3 p 5 .10 7 .15 9 .05 What is the probability that x is 5? What is the probability that x is no more than 5? Expected Value of x=E(x)? Variance? Standard Deviation? Click here to see answer by Fombitz(13828)

 Question 311189: A bag contains 4 yellow,3 pink,2 red, and 1 blue marbles. A marble is drawn at random with replacement. Find each probability. P(yellow,pink) P(blue, blue) P(red,pink,blue) Thankyou Click here to see answer by Fombitz(13828)

 Question 311184: Nigel keeps six CDs (Beatles, Duran Duran, Eminem, Five for Fighting, Gorillaz, and Styx) on a shelf in alphebetical order. If Nigel pulls them down and then puts them up in a random order, find the probability of P(Gorillaz CD is in the correct position). Click here to see answer by Fombitz(13828)

 Question 311251: A bowl contains only red and black marbles.There are x red marbles, with 2 more black marbles than red. If a marble is selected at random, what is the probability that it will be black? a 2/x b x/(x+2) c x/(2x+2) d (x+2)/(2x+2) e 2/(x+2) Click here to see answer by Fombitz(13828)

 Question 311235: Air Transportation data from 1969-1998 collected from www.air-transport.org Assume it is a binomial distribution (fatal vs not fatal) Year 1969 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 Accidents 7 2 6 7 6 7 2 2 3 5 4 0 4 4 4 1 4 2 4 3 Year 1989 90 91 92 93 94 95 96 97 98 Accidents 8 6 4 4 1 4 2 3 3 0 a.) Find the mean and standard deviation of the number of fatal air travel accidents in 1997. There were 8 million flights. b.) Could a person claim that 8 fatal crashes in a year are unusual? Explain. Click here to see answer by Fombitz(13828)

 Question 311295: Hi,I am trying to do a practice sheet to study for the final and I am really struggling, your help is really appreciated. The amount of soda a dispensing machine pours into a 12 ounce can of soda follows a normal distribution with mean of 12.03 ounces and a standard deviation of .02 ounces. The cans can hold only 12.05 ounces of soda. Every can that has more than 12.05 ounces of soda poured into it causes aa spill and the can needs to go through a special cleaning process before it can be sold. A. What proportion of the cans need to go through the cleaning process? B. How much soda would the cans need t hold if the company wanted to limit the percentage that needed to be cleaned because of spillage to 3%? Click here to see answer by stanbon(60771)

 Question 311228: The probability of getting an “A” in statistics is 0.2. Find the probability of exactly 3 students out of 8 getting an “A” Click here to see answer by fractalier(2101)

 Question 311362: A student is taking a standardized test consisting of multiple choice questions for which there are five options for each question. Seven points are awarded for each correct answer, but the student loses 2 points for an incorrect answer. Questions left blank neither receive nor lose points. What is the minimum number of options that the student should be able to rule out before making a guess on any particular question? Click here to see answer by Edwin McCravy(9717)

 Question 311402: What is the mean, median and mode of the following numbers: 68,72,50,77,76,68,78,68,50,72,61,74,77,76,69, Click here to see answer by Miceandwine(15)

 Question 311379: Is a registration number considered to be a ratio, interval, ordinal, or nominal? Click here to see answer by stanbon(60771)

 Question 311341: what percent of the babies born with each gestation period have a low birth rate (under 5.5 pounds) ? Explain your reasoning. A. under 28 weeks b. 32-35 weeks c 37-39 weeks d 42 weeks and over Click here to see answer by stanbon(60771)

 Question 311221: the proportion of students in private schools is around 11%. A random sample of 450 students from a wide geographic area indicated that 55 attended private schools. Estimate the true proportion of students attending private schools with 95% confidence. How does your estimate compare to 11%? Click here to see answer by stanbon(60771)

 Question 311432: A random sample of 10 miniature tootsie rolls was taken from a bag. Each piece was weighed n a very accurate scale. The results in grams were: 3.087,3.131,3.241,3.241,3.270,3.353,3.400,3.411,3.437,3.477 A)Construct a 90 percent confidence interval for the true mean weight. B)What sample size would be necessary to estimate the true weight with an error of +- 0.003 grams with 90 percent confidence? C)Discuss the factors which might cause variation in the weight of tootsie rolls during manufacture. (Data are from a project by MBA student Henry Scussel.) Tootsie Click here to see answer by stanbon(60771)

 Question 311424: Need to make a circle graph of the findings: A college's complaints survey was taken and found the top five complaints to be as follows: not enough time (27) hard math questions (48) more venidng machine choices (12) high cost of books(32)and no free copying machine (8). Click here to see answer by stanbon(60771)

 Question 311421: A random sample of 10 miniature tootsie rolls was taken from a bag. Each piece was weighed n a very accurate scale. The results in grams were: 3.087,3.131,3.241,3.241,3.270,3.353,3.400,3.411,3.437,3.477 A)Construct a 90 percent confidence interval for the true mean weight. B)What sample size would be necessary to estimate the true weight with an error of +- 0.003 grams with 90 percent confidence? C)Discuss the factors which might cause variation in the weight of tootsie rolls during manufacture. (Data are from a project by MBA student Henry Scussel.) Tootsie Click here to see answer by stanbon(60771)

 Question 311552: Salary offer You are applying for a job at two companies. Company A offers starting salaries with u = \$31,000 and o = \$1,000. Company B offers starting salaries with u = \$31,000 and o = \$5,000. From which company are you more likely to get an offer of \$33,000 or more? The u is the lowercase Greek letter (mu), I'm not sure what the other symbol stands for o? it looks like an o with a little hook on top? Click here to see answer by scott8148(6628)

 Question 311645: 20% of students who sit for the CPA examination pass it the first time. Find the probability that less than 17% of students in a sample of 500 who will sit for the examination will pass it the first time. Click here to see answer by stanbon(60771)

 Question 311128: . A sample of 40 golfers showed that their average score on a particular golf course was 85 with a standard deviation of 8. Answer each of the following (show all work): (A) Find the 95% confidence interval of the mean score for all 40 golfers. (B) Find the 95% confidence interval of the mean score for all golfers if this is a sample of 70 golfers instead of a sample of 40. (C) Which confidence interval is smaller and why? (Points :6) Click here to see answer by trelle(1)

 Question 311683: n is an integer chosen at random from the set {2,5,6} and p another integer chosen at random from the set {6,9,10}. What is the probability that the two numbers n and p are even? A) 2/9 B) 5/9 C) 4/9 D) 1/9 E) 7/9 Click here to see answer by stanbon(60771)

 Question 311675: To test the null hypothesis that the average lifetime for a particular brand of bulb is 700 hours versus the alternative that the average lifetime is different from 700 hours, a sample of 80 bulbs is used. If the standard deviation is 40 hours and α is equal to 0.05, what values for x will result in rejection of the null hypothesis (show all work). Click here to see answer by stanbon(60771)

 Question 311670: A soft drink company holds a contest in which a prize may be revealed on the inside of the bottle cap. The probability that each bottle cap reveals a prize is 0.2 and winning is independent from one bottle to the next. What is the probability that a customer must open three or more bottles before winning a prize (0.2)(0.2)(0.8) = 0.032 (0.8)(0.8)(0.2) = 0.128 (0.8)(0.8) = 0.64 1- (0.2)(0.2)(0.8) = .968 Thanks, Kim Click here to see answer by stanbon(60771)

 Question 311669: Out of the fifteen questions for homework I have 4 I am having difficulty with.A medical treatment has a success rate of 0.8. Two patients will be treated with this treatment. Assuming the results are independent for the two patients, what is the probability that neither one of them will be successfully cured. Thanks for all your help, Kim Click here to see answer by stanbon(60771)

 Question 311668: A short quiz has two true-false questions and one multiple-choice question with four choices. A student guesses at each question. Assuming the choices are all equally likely, what is the probability that the student gets all three correct. 1/32 1/3 1/8 1/16 Please walk me thru this problem I am trying to take this online stats class and am failing miserably. Thank you, Kim Click here to see answer by stanbon(60771)

 Question 311699: A box contains 74 brass washers, 86 steel washers and 40 aluminum washers, Three washers are drawn at random from the box without replacement. Determine the probability that all three are steel washers Click here to see answer by stanbon(60771)