Wetzel                                                                                                                                                                                                              

Math 120

Test #1

Write the symbol that represents each value in the space provided.

1.)  population standard deviation                      __________

2.)  correlation coefficient                                  __________

3.)  sample standard deviation                           __________

4.)  sample size                                                 __________

5.)  population mean                                         __________

6.)  sample mean                                              __________

Given the following sample set of test scores, answer questions 7-12.

                        {87, 93, 81, 75, 85, 100, 88, 97, 81, 93, 58, 56, 80, 93}

7.)  Find the mean.                                            8.)  Find the mode.

9.)  Find the median.                                         10.)  Find the range.

11.)   Find the standard deviation.

12.)  Construct a stem and leaf plot.

13.)  Given the following data set of quiz scores,

{85, 90, 91, 72, 83, 95, 88, 58, 71, 89, 87, 96, 64, 84, 99, 72, 50, 77}

a.)       Complete the frequency distribution table below showing 5 classes.

      b.)  Construct a relative frequency histogram.

14.)  Suppose the cost of gasoline is a normal distribution.  The average cost of regular unleaded gasoline is $2.47 per gallon with a standard deviation of $0.03 per gallon. 

a.)  What percentage of gas stations would you expect to charge between $2.38 and $2.56 per gallon?

b.)  What percentage of gas station would you expect to charge more than $2.44 per gallon?

15.)  Given the following table showing the temperature and corresponding coffee sales,…

a.)      find the correlation coefficient.

b.)      describe any correlation between the temperature and the number of coffee sales.     ( positive, negative, etc.)

c.)      write an equation for the regression line (the line of best fit).

d.)      if the temperature is 36 degrees, how much coffee would be expected to sell?

e.)  in your own works, explain how does the temperature effects the number of coffee sales.

f.)  construct a scatter plot.  What are the x-axis and y-axis dimensions when you have the calculator automatically zoom to fit the data?

x-min:______               x-max:_______

y-min:______               y-max:_______