1)

Twenty-Five different video games showing druguse were observed. The duration times of druguse (in seconds) were recorded. When using this sample for a t test of the claim that the population mean is greater than 95 sec, what does df denote, and what is its value?

What does df denote?

The value of df is

2)The claim is that weights (grams) of quarters made after

1964

have a mean equal to

5.670

g as required by mint specifications. The sample size is

n=35

and the test statistic is

t=2.322.

Use technology to find the P-value. Based on the result, what is the final conclusion? Use a significance level of

0.10.

State the null and alternative hypotheses.

H0:=

H1:

(Type integers or decimals. Do not round.)

3)In a study of pulse rates of men, a simple random sample of

146

men results in a standard deviation of

11.7

beats per minute. The normal range of pulse rates of adults is typically given as

60

to

100

beats per minute. If the range rule of thumb is applied to that normal range, the result is a standard deviation of

10

beats per minute. Use the sample results with a

0.05

significance level to test the claim that pulse rates of men have a standard deviation equal to

10

beats per minute; see the accompanying StatCrunch display for this test. What do the results indicate about the effectiveness of using the range rule of thumb with the "normal range" from

60

to

100

beats per minute for estimating

in this case?

Assume

that the simple random sample is selected from a normally distributed population.

One sample variance hypothesis test: 02 : Variance of variable Ho : 02 = 100 HA : 02 # 100 Hypothesis test results: Variable Sample Var. DF Chi-Square Stat P-value PULSE 137.19704 145 198.93571 0.0040