Review for test:

1.  Use data on page 170, 3.74

a)      How many castings are rejected due to sand in 1st shift?

b)      How any castings are rejected due to breakage in 3rd shift?

c)      How many castings are rejected in 3rd shift?

d)      How many castings were broken in all?

e)      What percent of third shift casting are rejected due to breakage?

f)        What percent of broken castings are from 3rd shift?

g)      What percent of all castings are broken?

  1. Here are grades for Mr. Gillam’s two probability and statistics classes:

Class one: 74, 87, 93, 91, 85, 87, 90, 81, 87, 79, 84, 94, 92, 47, 73, 81, 60, 92, 85, 77, 71, 77, 91, 79, 92

Class two: 89, 83, 70, 74, 94, 89, 77, 83, 79, 92, 97, 70, 84, 90, 81, 58, 69, 65, 88, 91, 88, 88

            a) create comparative boxplots of the data.

b)      Compare the two classes. Be sure to compare in terms of shape, center and spread.

  1. Page 171 3.83 a – f

g)      Interpret the slope in context of the problem.

 

Answers:

1. a) 87                  b) 20                c) 167              d) 49               

e) 20/167 = 11.98%                       f)  20/49 = 41.82 %                 g)  49/515 = 9.51%

2. 

Both are skew left

Median of class two is less

IQR of class two is slightly larger than class one

3. 

a)  

b) Strong, linear, positive correlation

c) y = 3.29x + 25.23          d) 71, 91         

e)  Yes, between 70 and 90 seems reasonable for summer temperatures at night

f)  78

g)  For every increase of one chirp, the temperature rises 3.29 degrees.