# Ch 6: Test Yourself

1.  For each of the following variables in a study, list the one best measure of central tendency you can use to describe the data, and a graph to depict the distribution of values (pick any one if more than one can be used)?

Statistic                    Graph/Chart

 a)  Grades on statistics exam b)  region of country living in c)  number of hours doing exercise in a typical week d)  birth order e)  type of music preferred

2.  Fifth grade teacher reports on the reading exam results for the class. The grades were approximately normally distributed with a mean of 70 and a standard deviation of 10, what percentage of students received grades:

a) less than 70?

b) greater than 90?

c) between 60 and 80?

d) what is the mode on this exam?

e) what is the median grade on this exam? ______ 70

3.  There are 100 candies in a bag: 60 red ones, 30 blue, and 10 yellow.

(a) what are the odds of selecting a red one?

(b) what is the probability of choosing a yellow one or a blue one? 4. Why is this a statistician’s favorite joke? 1.                                                                   Statistic                Graph/Chart

 a)  Grades on statistics exam mean Histogram or frequency graph b)  region of country living in mode Bar or pie chart c)  number of hours doing exercise in a typical week mean Frequency graph d)  birth order median Bar or pie chart e)  type of music preferred mode Bar or pie chart

2.

a)  50%

b) around 2% (2.27% exactly)

c) around 68%  (68.26% exactly)

d)  70

e) 70

3.

a) 60/100 = .60 or 60%

b) 10/100 + 30/100 = .40 or 40%

4. Remember Variance and Standard Deviation? Opinion Polls? The true answer is within plus or minus 5 feet in this joke, as someone who knows statistics would say!