1. Once a distribution has been displayed by a stemplot or histogram, what important features should we attempt to describe? (8 points)
 
 
 

2. A store takes a sample of 17 days of the year and records the number of boxes of a certain type of cereal sold. Use the data given below to answer the following questions:

19, 19, 7, 16, 17, 18, 17, 19, 20, 17, 16, 18, 13, 26, 18, 17, 16

a. Complete the following 5-number summary for this data by finding the median, M. (6 points)

Minimum = 7        Q₁ = __           M = ____     Q₃ = 19          Maximum = 26

b. Use your completed 5-number summary to construct a modified boxplot, label any outliers with an *. (6 points)

    8    10   12   14     16    18    20    22     24    26
__|___|____|___|____|____|___|____|____|___|___

3. There are three basic principles of statistical design of experiments. Name them. (6 points)
 
 

Answer ______________, and _______________, and ______________

4. Use the attached copy of TABLE A to determine the proportion of observations from a standard normal distribution and shade in the area under the curve that corresponds to the inequality below: (6 points)

1.23 <  Z  <  2.64                                                         Answer ___________

5. Fill in the blank. In a time series, a persistent, long term rise or fall is called a _________. (4 points)
 
 
 
 

6. What is statistical inference? (6 points)
 
 
 
 

7. Fill in the blank. If the points in a ____________________ plot lie close to a straight line, the plot indicates that the data are normally distributed. (4 points)
 

8. Scores on final exams for a certain large course are typically approximately normally distributed with a mean of 72 and a standard deviation of 12. The professor says that the top 10% will receive an A grade. At least what score must you get on the final to get an A? Drawing a picture may help. (8 points)

                                                            Answer = ________________
 
 

9. The Electroencephalogram (EEG) is a device used to measure brain waves. Neurologists have found that the peak EEG frequency in children increases with age. You will study this by completing a simple linear regression of y = peak EEG frequency measured in hertz on
x = age in years. The ages and EEG peaks of four children are given here.  Use this information to answer the questions below.
 

 a. Find the mean and standard deviation of the four children's ages. (10 points)

Answer mean = __________ and s = ________________

b. Find the slope of the least squares regression line of y on x using this data. Show all your work. (8 points)

Answer ________________

10. Use the attached copy of Table B Random Digits to select a simple random sample of size n = 2 from the letters A through Z (number the letters 01 through 26). Begin on line 120 of Table B and go across the 8 columns of numbers on the left hand side of the page then continue to line 121 as necessary to take your sample. Underline the sample values on Table B and record them below. Cross out any values in the table that you skip. (6 points)
 
 

Answer the two sample letters are _____ and ____

11. Each person in a group of 300 students was identified as male or female and then asked whether he or she preferred taking courses in math, social science, or natural sciences. Use the table of results below to answer the following question:
 

Give (in percentages) the conditional distribution of Favorite Subject Area for female students. (10 points)
 

y hat = -2.2 + 2.3x     with     r = 0.92

a. One child in the study had a flexibility score of 3 and a creativity score of 5. Give the residual for this observation. (6 points)

b. If we had the data that was used for fitting this regression, what else should we do to assess whether linear regression is appropriate or not. (6 points)