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

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 Question 142971: Please help me understand probability and if i set up this problem correctly? I am struggle with knowing how to lay out to get the correct answers. This is on a hand out sheet so it is not my math book. Indicated probability. A box contains 20 blue marbles, 16 green marbles and 14 red marbles. Two marbles are selected at random without replacement. Let E be the event that the first marble selected is green. Let F be the event that the second marble selected is green. Find P(F/E). First i added the total number of marbles 20+16+14 = 50 Then I put 16/50 * 15/49 = 24/25 =.96 = 96% Would the P(16/15) = 96%? I am not sure if this is correct. Thank You. Click here to see answer by oscargut(1838)

 Question 142941: Last year the records of Dairy Land Inc., a convenience store chain, showed the mean amount spent by a customer was \$30. A sample of 40 transactions this month revealed the mean amount spent was \$33 with a standard deviation of \$12. At the 0.05 significance level, can we conclude that the mean amount spent has increased? What is the p-value? Follow the five-step hypothesis testing procedure. Click here to see answer by stanbon(60778)

 Question 142940: A 1990 census report revealed that the mean distance that U. S. citizens live from their birthplace is 50 miles and that the standard deviation is 15 miles. A random sample of 49 residents of your city yielded a mean distance of 56 miles. Click here to see answer by stanbon(60778)

 Question 143038: A bag contains 4 red, 6 white, and 9 blue marbles. How many ways can 5 marbles be selected if 2 are one color, and 3 are another? Click here to see answer by stanbon(60778)

 Question 143037: A furniture buyer has ordered 100 grandfather clocks from an overseas manufacturer. Four clocks are damaged in shipment, but the packaging shows no indication of such damage. If a dealer buys 6 clocks without examining the contents, what is the probability that she does not have a damaged clock? Click here to see answer by stanbon(60778)

 Question 143042: There are 12 members of the basketball team. At each game, the coach selects a group of five team members to start the game. For how many games could the coach make different selections? Click here to see answer by stanbon(60778)

 Question 143041: Jane visits 2 doctors, Dr. Skaer and Dr. Queern, for a diagnosis. The probability that Dr. Skaer correctly diagnoses a disease is 97/100, and the probability that Dr. Queern correctly diagnosises a disease is 93/100. What is the probability that at least one of the two doctors makes the correct diagnosis? Click here to see answer by edjones(7794)

 Question 143040: A bag contains 15 billiard balls, numbers consecutively from 1 to 15. Six balls are selected at random. What is the probability that the sum of the numbers on the billiard balls will be odd? Click here to see answer by Edwin McCravy(9719)
 Question 143040: A bag contains 15 billiard balls, numbers consecutively from 1 to 15. Six balls are selected at random. What is the probability that the sum of the numbers on the billiard balls will be odd? Click here to see answer by edjones(7794)

 Question 143058: How many 5-digit numbers exist between 65,000 and 69,999 if each number has no repeated digits? Click here to see answer by vleith(2825)

 Question 143059: The United States Congress is made up of 100 members of the Senate and 435 members of the House of Representatives. How many 5-member senatorial committees are possible? Click here to see answer by stanbon(60778)

 Question 143057: If the probability that the team from the National League will win is 3/5 for each game, what is the probability that the National League team will win the World Series? Click here to see answer by stanbon(60778)

 Question 143172: Marty bought 5 lbs. of apples for 98 cents a pound. a week later, she bought 7 lbs. of apples for 74 cents. what was the average price per pound that marty paid for apples? Click here to see answer by jojo14344(1513)

 Question 143246: A sample of 40 observations is selected from one population. The sample mean is 102 and the sample STDEV is 5. A second sample of 50 observations is selected from a second population. That sample mean is 99 and the STDEV is 6. Conduct the following test of hypotheses using the 0.04 significance level: H(0): m(1) = m(2) H(1): m(1) is not equal to m(2) a. Is this a one-tailed or a two-tailed test? b. State the decision rule. c. Compute the value of the z- test statistic. d. State your decision regarding H(0). Please answer in excell spreadsheet if possible. Click here to see answer by stanbon(60778)

 Question 143220: Do a larger proportion of people own cats live in houses or apts? Group 1 Houses Group 2 Apts Number who own cats: x1= 833 x2 = 692 Number Surveyed: n1 = 850 n2 = 740 I need to perform the five step hypothesis test. Click here to see answer by stanbon(60778)

 Question 143171: Abe, brian, and Carmela share the responsibility of caring for the family pets. during a seven day week, abe and brian each take 3 days and carmela takes the other one. in how many different orders can the days of a week be assigned? Click here to see answer by stanbon(60778)

 Question 143150: A dinner dance is attended by 12 married couples. In how many ways may a dancing couple be formed if husband and wife (A) do not dance together? (B) may dance together? (C) must dance together? Click here to see answer by stanbon(60778)

 Question 143142: he Rocky Mountain district sales manager of Rath Publishing, Inc., a college textbook publishing company, claims that the sales representatives make an average of 40 sales calls per week on professors. Several reps say that this estimate is too low. To investigate, a random sample of 28 sales representatives reveals that the mean number of calls made last week was 42. The standard deviation of the sample is 2.1 calls. Using the 0.05 significance level, can we conclude that the mean number of calls per salesperson per week is more than 40? (Remember to complete the 5 step hypothesis testing procedure to answer this question). Click here to see answer by stanbon(60778)

 Question 143056: If a thumbtack is dropped, the probability of its landing point up is 2/5. Mrs. Johnson drops 10 tacks whle putting up the lunch menus for the week on the bulletin board. Find the probability that at least 6 point up. Click here to see answer by stanbon(60778)

 Question 143140: 2. A 1990 census report revealed that the mean distance that U. S. citizens live from their birthplace is 50 miles and that the standard deviation is 15 miles. A random sample of 49 residents of your city yielded a mean distance of 56 miles. a. Set up the null and alternative hypotheses to test if the mean distance from residence to birthplace for people living in your city differs from the census report. b. Test your hypothesis using α = 0.01. c. Find the p value. d. Based on the results of the study, what can you conclude? Click here to see answer by stanbon(60778)

 Question 143139: Last year the records of Dairy Land Inc., a convenience store chain, showed the mean amount spent by a customer was \$30. A sample of 40 transactions this month revealed the mean amount spent was \$33 with a standard deviation of \$12. At the 0.05 significance level, can we conclude that the mean amount spent has increased? What is the p-value? Follow the five-step hypothesis testing procedure. Click here to see answer by stanbon(60778)

 Question 143424: When three coins are tossed what is the probability that they all land with a head showing? Round to 2 decimal places. Click here to see answer by solver91311(18785)

 Question 143423: One of the 24 pieces of fruit in a box is selected at random. If the probability that it is an orange is 3/8 then how many oranges are in the box? Click here to see answer by stanbon(60778)
 Question 143423: One of the 24 pieces of fruit in a box is selected at random. If the probability that it is an orange is 3/8 then how many oranges are in the box? Click here to see answer by solver91311(18785)

 Question 143327: Part 2) Exercise #2 The null and alternate hypotheses are: H(0): m(1) = m(2) H(1): m(1) is not equal to m(2) A random sample of 10 observations from one sample revealed a sample mean of 23 and a sample STDEV of 4. A random sample of 8 observations from another population revealed a sample mean of 26 and a sample STDEV of 5. At the 0.05 significance level, is there a difference between the population means? Also, (a) state the decision rule, (b) compute the pooled estimate of the population variance,(c) compute the t-test statistic, (d) state your decision about the null hypothesis, and (e) estimate the p-value. Click here to see answer by stanbon(60778)

 Question 143448: a candy jar has red and black licorice sticks. There are 12 more red licorice sticks than black. If jorge chooses one licorice stick, without looking, there is a 60% probability that it is red. How many red licorice sticks are in the candy jar? Click here to see answer by stanbon(60778)

 Question 143671: Sean tells perspective clients that the probability of rain at the dive location is .2 each day. Which expression can be used to calculate the probability that it will rain on exactly 5 days of the 7 days at the dive location? Click here to see answer by edjones(7794)

 Question 143705: there is a 30% chance of rain today or a 60% chance of rain tommorrow, what is the chance of rain today or tommorrow? & there is a 30% chance of rain today and a 60% chance of rain tomorrow, what is the chance of rain today and tomorrow? Thanks Click here to see answer by rapaljer(4670)

 Question 143704: You draw 2 cards from a well shuffled deck of 52 cards, after you draw the first card, you do not replace it in the deck. what is the probability of drawing an ace of spades on your first draw is 1/52 what is the probability of p(get a Q of hearts in teh 2nd draw/get ace of spades in the first) and you draw 2 cards from a well shuffled deck of 52 cards, after you draw the first card you replace it in the deck. what is the probability of drawing an ace of spades on your first draw is 1/52 what is the probability of p(get a Q of hearts in the 2nd draw/ get ace of spades in the first) Click here to see answer by rapaljer(4670)

 Question 143831: Can you help me with this problem? I think i am on the right track but am not sure. Any help would be appreciated. I am not sure on how to find the percentiles on problem # 80. Suppose that the mean salary for your profession is \$53,000 with a standard deviation of \$2,500. To what percentile does your salary of \$57,000 correspond? This is how i worked it out but i think i am missing a piece. I took the mean which is \$53,000 and subtracted \$57,000 from it which gave me a -\$4000 and then divided it by the standard deviation which is \$2,500 which gave me -1.6. But now what do i do now to get the percent? Any guidance you can provide would truly help. Thankyou Click here to see answer by vleith(2825)

 Question 143834: Can you please tell me If I set this up and worked it out correctly. Question: Analyzing customer service. The distribution of times that customers spend waiting in line in a supermarket has a mean of 3.6 minutes and a standard deviation of 1.2 minutes. For this distribution find the raw score that corresponds to a z-score of -1.3. Here is how I set it up -1.3= x-3.6 divided by 1.2 Then i multiplied both sides by 1.2 giving me the equation of -1.56 = X-3.6, -1.56 +3.6 = X, 2.04 = X X = 2.04 Raw score is 2.04 that corresponds to the z-score of -1.3. Can you tell me if this is the correct way to work this out? Thank You. Click here to see answer by vleith(2825)

 Question 143863: You have a three card deck containing a king, a queen , and a jack. You draw a random card, then put it back and draw a second random card. calculate the probability that you draw exactly one jack. Click here to see answer by stanbon(60778)

 Question 143900: A bag has yellow marbles and brown marbles. Half of the brown marbles are made of plastic. A marble is selected at random from the bag. What is the probability that it is a brown, plastic marble? Click here to see answer by scott8148(6628)

 Question 143676: Problem 10-36. The Rutter Nursery Company packages their pine bark mulch in 50-pound bags. From a long history, the production department reports that the distribution of the bag weights follows the normal distribution and the standard deviation of this processis 3 pounds per bag. At the end of each day, Jeff Rutter, the production manager, weighs 10 bags and computes the mean weight of the sample. Below are the weights of 10 bags from today's production. 45.6 47.7 47.6 46.3 46.2 47.4 49.2 55.8 47.5 48.5 a. Can Mr. Rutter conclude that the mean weight of the bags is less than 50 pounds? Use the .01 significance level. b. In a brief report, tell why Mr. Rutter can use the z distribution as the test statistic. c. Compute the p-value. Click here to see answer by stanbon(60778)

 Question 143677: Problem 11-38. Two boats, the Prada (Italy) and the Oracle (U.S.A.), are competing for a spot in the upcoming America's Cup race. They race over a part of the course several times. Below are the sample times in minutes. At the .05 significance level, can we conclude that there is a difference in their mean times? Boat Times (minutes) Prada (Italy) 12.9 12.5 11.0 13.3 11.2 11.4 11.6 12.3 14.2 11.3 Oracle (U.S.A.) 14.1 14.1 14.2 17.4 15.8 16.7 16.1 13.3 13.4 13.6 10.8 19.0 Click here to see answer by stanbon(60778)

 Question 143976: Consider a tree diagram representing all the possible final outcomes in the following scenario: You buy a fancy sports car with 7 choices of wheel covers, 4 choices of stereo model, 8 upholstery packages, and a choice of clear or tinted glass windows. How many "leaves" does the tree have? Click here to see answer by vleith(2825)

 Question 143974: You have 7 friends who want to go to a concert with you, but you only have room in your car for 2 of them. To avoid accusations of favoritism, you have your friends draw straws: There are 3 long and 2 short straws, and the short straws win. How many possible pairs of friends could be chosen in this way? Click here to see answer by stanbon(60778)

 Question 144043: You toss 3 coins. What is the probability that you get exactly 2 heads, given that you get at least one head? Click here to see answer by stanbon(60778)

 Question 144061: A high school club has 10 members. The faculty advisor selects members at random to fill leadership posistions for president, vice president, treasurer, and secretary. Find the probability that Mark, one of the club members, is selected for a leadership posistion. Click here to see answer by edjones(7794)

 Question 144059: you need to select a 4 character password for a computer account. Any digit 0-9 and any letter A-Z can be used for a character, and digits and letters can be repeated. How many possible passwords are there? Click here to see answer by edjones(7794)

 Question 144045: A coin was flipped 60 times and came up heads 38 times. (a) At the .10 level of significance, is the coin biased toward heads? Show your decision rule and calculations. (b) Calculate a p-value and interpret it. Click here to see answer by stanbon(60778)

 Question 144046: The Web-based company Oh Baby! Gifts has a goal of processing 95 percent of its orders on the same day they are received. If 485 out of the next 500 orders are processed on the same day, would this prove that they are exceeding their goal, using α = .025? (See story.news.yahoo.com accessed June 25, 2004.) Click here to see answer by stanbon(60778)

 Question 144048: An auditor reviewed 25 oral surgery insurance claims from a particular surgical office, determining that the mean out-of-pocket patient billing above the reimbursed amount was \$275.66 with a standard deviation of \$78.11. (a) At the 5 percent level of significance, does this sample prove a violation of the guideline that the average patient should pay no more than \$250 out-of-pocket? State your hypotheses and decision rule. (b) Is this a close decision? Click here to see answer by stanbon(60778)