Math 3339 test file,, Study Guides, Projects, Research of Statistics

Download Math 3339 test file, and more Study Guides, Projects, Research Statistics in PDF only on Docsity! PRINTABLE VERSION Final You scored 42 out of 45 Question 1 Your answer is CORRECT. Which of the following is a measure of spread? a) median b) mode c) standard deviation d) third quartile e) mean Question 2 Your answer is CORRECT. a) 0.116 b) 0.256 c) 0.593 d) 0.884 e) 0.407 Question 3 Your answer is CORRECT. A service center receives an average of 0.8 customer complaints per hour. Management's goal is to receive fewer than three complaints each hour. Assume the number of complaints follows the Poisson distribution. Determine the probability that exactly four complaints will be received during the next eight hours. a) 0.235 , find P (B | A) .Given that P (A) = 0.27, P (B) = 0.43, and P (A ∩ B) = 0.11 P(B|A) = P( A∩B)/P(A) P(B|A) = 0.11/0.27 P(B|A) = 0.4074074 Standard Deviation b) 0.116 c) 0.008 d) 0.765 e) 0.999 Question 4 Your answer is CORRECT. The following table displays the results of a sample of 100 in which the subjects indicated their favorite ice cream of three listed. The data are organized by favorite ice cream and age group. What is the probability that a person chosen at random will be under 20 years old if he or she favors chocolate? Age Chocolate Vanilla Strawberry Over 40 12 8 10 20-40 15 8 12 Under 20 11 16 8 a) b) c) d) e) Question 5 Your answer is CORRECT. Suppose that in a large metropolitan area, 81% of all households have cable tv. Suppose you are interested in selecting a group of six households from this area. Let X be the number of households in a group of six households from this area that have cable tv. For what proportion of groups will at most two of the households have cable tv? a) 0.913 b) 0.014 11 38 89 100 11 100 11 30 27 38 pbinom(2,6,0.81) [1] 0.01407597 # of under 20 years(chocolate) /Total (chocolate) 11/38 dpois(4,0.8*8) [1] 0.1161513 Determine the p-value for the data. a) 0.0005 b) 0.0015 c) 0.0551 d) 0.1955 e) 0.0007 Question 11 Your answer is CORRECT. A random sample of 144 cans of fruit nectar is drawn from among all cans produced in a run. Prior experience has shown that the distribution of the contents has a mean of 13.22 ounces and a standard deviation of 2.16 ounce. What is the probability that the average contents of the 144 sample cans is less than 13.00 ounces? a) 0.222 b) 0.778 c) 0.277 d) 0.889 e) 0.111 Question 12 Your answer is CORRECT. If the P-value is larger than the level of significance α, then the researcher should __________ at level α. a) Reject H0 b) Accept H0 c) Fail to reject H0 Question 13 Your answer is INCORRECT. For a specific location in a particularly rainy city, the time a new thunderstorm begins to produce rain (first drop time) is uniformly distributed throughout the day and independent of this first drop time for the if p value is greater than 0.05 (alpha) than it is fail to reject (FRHo) pnorm(13.00,13.22,2.16/sqrt(144)) [1] 0.1108118 pf(84.17/15.29,6,21, lower.tail=FALSE) [1] 0.001470767 surrounding days. Given that it will rain at some point both of the next two days, what is the probability that the first drop of rain will be felt between AM and PM on both days? a) 0.9540 b) 0.0460 c) 0.2188 d) 0.2146 e) 0.0479 f) None of the above. Question 14 Your answer is CORRECT. The one-sample t statistic for a test of H0: μ = 12 vs. Ha: μ < 12 based on n = 17 observations has the test statistic value of t = −1.58. What is the p-value for this test? a) 0.367 b) 0.000 c) 0.067 d) 0.933 e) 0.134 Question 15 Your answer is CORRECT. A student is taking their Statistics final exam. For a particlar problem there are three versions. All versions ask for a value of so that , where varies depending on the problem version. Assume that follows the following distrubution: Find . a) b) c) 9 : 40 2 : 55 c P (Z ≤ c) = A A A P (A = 0.62) = , P (A = 0.77) = , P (A = 0.66) = 1 2 1 4 1 4 E[c] 0.874 0.441 1.126 qnorm(0.62) [1] 0.3054808 > qnorm(0.77) [1] 0.7388468 > qnorm(0.66) [1] 0.4124631 > (0.305*1/2)+(0.7388*1/4)+(0.4124*1/4) [1] 0.4403 pt(-1.58,16) [1] 0.06683549 df = n-1 = 17-1 = 16 9:40 AM - 2:55 PM : 5 hr and 15 min 15/60 [1] 0.25 > 5+0.25 [1] 5.25 > 5.25/24 [1] 0.21875 > 0.21875*0.21875 [1] 0.04785156 d) e) f) Cannot be determined. Question 16 Your answer is CORRECT. This is a written question, worth 11 points. DO NOT place the problem code on the answer sheet. A proctor will fill this out after exam submission. Show all steps (work) on your answer sheet for full credit. Problem Code: 1633 A person's muscle mass is expected to decrease with age. To explore this relationship in women, a nutritionist randomly selected 60 women aging from age 40 to 79 and measured their muscle mass. Using age as the explanatory variable and the muscle mass as the dependent variable, computer output of the data is as follows (the p-values are intentionally left blank): Predictor Coef StDev T P Constant 101.50 5.85 17.35 --- Age − 0.27 0.09 − 3.00 --- Part a: What is the regression equation? Part b: Calculate the 99% confidence interval of the slope of the regression line. Part c: Use the information provided to test whether there is a significant relationship between a person's age and muscle mass at the 5% level. a) I have placed my work and my answer on my answer sheet. b) I want to have points deducted from my test for not working this problem. Question 17 Your answer is CORRECT. This is a written question, worth 11 points. DO NOT place the problem code on the answer sheet. A proctor will fill this out after exam submission. Show all steps (work) on your answer sheet for full credit. Problem Code: 1723 Suppose the random variable has CDF given by the function 0.984 0.852 X ⎧