1) For the data: 68 92 134 151 78 94 112

find: sample mean = ____________ sample standard deviation = ___________ range = _____________ median = _____________ sample size = __________

2) Exam scores for 30 students: 41 61 64 68 70 74 77 79 81 83 83 85 87 87 89 91 92 92 92 92 93 93 93 94 94 94 95 97 98 99

a) In the space below, create a grouped frequency distribution table, using 40-49 as the first class.

b) Determine the five-number summary. _________________________________

c) In space below, draw a histogram.

d) In space below, draw the boxplot.

e) Identify the shape. ___________________________

f) Find the interquartile range. _________________

3) Data were collected from 6 students: x = stress score on morning of test; y = grade on test

x: 4 7 9 10 6 6

y: 98 91 65 60 96 88

a) Draw a scatterplot in space below.

b) Determine the value of r. ________________

c) Give the direction and strength of the correlation. _____________________________

d) Find the equation of the regression line. __________________________

e) Predict the grade for a student with stress level 9. ____________

f) Use the result of e) to find the residual for the data point (9,65). ___________

g) Circle the correct choice and fill in the blank: For each additional point on the stress score, the grade for a student (increases, decreases) on average by about _______ points. h) Fill in the blank: ______ % of the variation in grades can be explained by the stress score.

i) Fred's stress score was 14 hours a week. Will the regression equation accurately predict his grade? Explain.

j) It turned out that, for the six students sampled, the correlation between the number of hours spent studying and the grade was r = +.733. Is this a stronger correlation than the one between stress score and grade? __________

4) 200 people from various demographics (geezer, boomer, zoomer) were asked if they felt hopeful or fearful after hearing the day's news. Results:

geezer boomer zoomer

hopeful 18 40 17

fearful 42 55 28

What is the probability that a person surveyed is:

a) a geezer? ________

b) not a geezer? ________

c) hopeful and a zoomer ________

d) fearful, given that the person is a boomer? ________

e) a zoomer, given that the person is hopeful? ________

5) Scores are normally distributed with mean = 350 and standard deviation = 60.

a) What is the probability that a score is less than 220? _________

b) What percent of scores are between 272 and 458? _________

c) What percent of scores are greater than 400? __________

d) What data value has 33% of the scores below it? __________

e) If a random sample of size 144 is chosen, what is the probability that the sample mean is less than 357? __________

6) In a simple random sample of 36 shoppers at Greedgate Mall, the sample mean amount spent last week was $259.48, with a sample standard deviation of $39.18.

a) Find a 95% confidence interval for the true mean weekly amount spent last week by Greedgate shoppers. ______________________________________

b) Will this interval allow us to conclude that the mean amount spent is less than $275? Explain.

7) 64 out of a simple random sample of 400 students liked their online math course.

a) Find a 99% confidence interval for the true proportion of students who liked their online math course. ______________________________

b) Will this interval allow us to conclude that fewer than 20% of all students liked their online math course? Explain.

8) Careful analyssis of a random sample of n=25 pages of a Huge Govermnent Document published by the Office Of Printed Statistical Information (OOPSI) revealed a mean of, 5.2 spellling and/or erorrs of grammer per page And!! the sample standard deviation (,s) of the number of erorrs per page is 3.8. Does this data provide significant evidence (at, the, 5% level) that the true mean number of erorrs per page is less than 7 and thus good, enough for govermnent work? State null and alternative hypotheses, calculate the test statistic, determine the Pvalue, and state your conclusion.