Question 13 (1 point)
A statistics professor wants to examine the number of hours that
seniors and freshmen study for the final. Specifically, the
professor wants to test if the average number of hours that seniors
study is greater than the average number of hours that freshmen
study. If the seniors are considered group 1 and the freshmen are
considered group 2, what are the hypotheses for this scenario?
Question 13 options:

1)

H_{O}: μ_{1} =
μ_{2}
H_{A}: μ_{1} ≠ μ_{2} 


2)

H_{O}: μ_{1} ≤
μ_{2}
H_{A}: μ_{1} > μ_{2} 


3)

H_{O}: μ_{1} >
μ_{2}
H_{A}: μ_{1} ≤ μ_{2} 


4)

H_{O}: μ_{1} ≥
μ_{2}
H_{A}: μ_{1} < μ_{2} 


5)

H_{O}: μ_{1} <
μ_{2}
H_{A}: μ_{1} ≥ μ_{2} 

Question 14 (1 point)
Does the amount of hazardous material absorbed by the bodies of
hazardous waste workers depend on gender? You want to test the
hypotheses that the amount absorbed by men (group 1) is greater
than the amount absorbed by women (group 2). A random sample of 286
male workers and 168 female workers showed an average lead
absorption in the blood of 14.84 (SD = 1.163) and 14.75 (SD =
0.976), respectively (measured in micrograms/deciliter). Assuming
that the population standard deviations are the same, perform a two
independent samples ttest on the hypotheses Null Hypothesis:
μ_{1} ≤ μ_{2}, Alternative Hypothesis:
μ_{1} > μ_{2}. What is the test statistic and
pvalue of this test?
Question 14 options:

1)

Test Statistic: 0.844, PValue:
0.1996 


2)

Test Statistic: 0.844, PValue: 0.3992 


3)

Test Statistic: 0.844, PValue:
0.8004 


4)

Test Statistic: 0.844, PValue: 0.8004 


5)

Test Statistic: 0.844, PValue: 0.1996 

Question 15 (1 point)
The owner of a local golf course wants to examine the difference
between the average ages of males and females that play on the golf
course. Specifically, he wants to test if the average age of males
is different from the average age of females. If the owner conducts
a hypothesis test for two independent samples and calculates a
pvalue of 0.9205, what is the appropriate conclusion? Label males
as group 1 and females as group 2.
Question 15 options:

1)

The average age of males is significantly
different from the average age of females. 


2)

We did not find enough evidence to say a
significant difference exists between the average age of males and
females. 


3)

We did not find enough evidence to say the
average age of males is larger than the average age of
females. 


4)

The average age of males is equal to the
average age of females. 


5)

We did not find enough evidence to say the
average age of males is less than the average age of females. 

Question 16 (1 point)
The federal government recently granted funds for a special
program designed to reduce crime in highcrime areas. A study of
the results of the program in highcrime areas of Miami, Florida,
are being examined to test the effectiveness of the program. The
difference in crimes reported is calculated as (crimes after 
crimes before). You want to test whether the crimes reported after
is different from those reported before and, thus, the hypotheses
are as follows: Null Hypothesis: μ_{D} = 0, Alternative
Hypothesis: μ_{D} ≠ 0. You perform a paired sample ttest
and see a pvalue of 0.0018. What is the appropriate
conclusion?
Question 16 options:

1)

The average difference in crimes reported
is significantly different from 0. There is a significant
difference in crimes reported due to the program. 


2)

The average difference in crimes reported
is significantly less than 0. The average number of crimes reported
was higher before the program. 


3)

We did not find enough evidence to say the
average difference in crimes reported was not 0. The program does
not appear to have been effective. 


4)

The average difference in crimes reported
is equal to 0. 


5)

The average difference in crimes reported
is significantly larger than 0. The average number of crimes
reported was higher after the program. 

Question 17 (1 point)
In the year 2000, the average car had a fuel economy of 20.9
MPG. You are curious as to whether the average in the present day
is less than the historical value. The hypotheses for this scenario
are as follows: Null Hypothesis: μ ≥ 20.9, Alternative Hypothesis:
μ < 20.9. If the true average fuel economy today is 22.1 MPG and
the null hypothesis is not rejected, did a type I, type II, or no
error occur?
Question 17 options:

1)

Type II Error has occurred 


2)

We do not know the degrees of freedom, so
we cannot determine if an error has occurred. 


3)

Type I Error has occurred. 


4)

We do not know the pvalue, so we cannot
determine if an error has occurred. 


5)

No error has occurred. 
