1)A sample of8 measurements, randomly selected from a normally distributed population, resulted in a sample mean,x=9.6and sample standard deviations=1.51. Using=0.05, test the null hypothesis that the mean of the population is9.5 against the alternative hypothesis that the mean of the population,<9.5 by giving the following:

(a)the degree of freedom

(b)the criticalt value

(c)the test statistic

2)In a sample of 40 grown-ups, the mean assembly time for a boxed swing set was 1.85 hours with a standard deviation of 0.44331 hours. The makers of this swing set claim the average assembly time is less than 2 hours.

(a) Find the test statistic

(b) Test their claim at the 0.01 significance level.

Critical value:_______

(c) Test their claim at the 0.05 significance level.

Critical value: _______

3)The effectiveness of a new bug repellent is tested on14 subjects for a 10 hour period. (Assume normally distributed population.) Based on the number and location of the bug bites, the percentage of surface area exposed protected from bites was calculated for each of the subjects. The results were as follows: x=92,s=11

The new repellent is considered effective if it provides a percent repellency of at least89. Using=0.05, construct a hypothesis test with null hypothesis=89 and alternative hypothesis>89 to determine whether the mean repellency of the new bug repellent is greater than89 by computing the following:

(a)the degree of freedom

(b)the criticalt value

(c)the test statistics

4)Test the claim that for the population of statistics final exams, the mean score is70 using alternative hypothesis that the mean score is different from70.Sample statistics includen=21,x=71,ands=17.Use a significance level of=0.01.(Assume normally distributed population.)

The test statistic is____

The positive critical value is_____

The negative critical value is_____

5)The hemoglobin count (HC) in grams per 100 milliliters of whole blood is approximately normally distributed with population mean 14 for healthy adult women. Suppose a female patient has had 18 laboratory blood tests during the past year. Her average HC is 11.73 with s = 1.78. Is there evidence that her average HC is not 14?

(a) State the null and alternative hypotheses: (Type "mu" for the symbol

, e.g.mu>1for the mean is greater than 1,mu<1for the mean is less than 1,mu not = 1for the mean is not equal to 1)

H₀:_____

H_a:_____

(b) Find the test statistic, t =_____