Need answers to these questions

Ch.9 Questions Part 21.) A random sample of 51 adult coyotes in a region of northern Minnesota showed the average
age to be x = 2.05 years, with sample standard deviation s = 0.86 years. However, it is thought
that the overall population mean age of coyotes is 𝜇 = 1.75. Do the sample data indicate that
coyotes in this region of northern Minnesota tend to live longer than the average of 1.75 years?
Use 𝛼 = 0.01.
A.) What is the level of significance?
B.) What is the value of the sample test statistic? (Round your answer to three decimal places.)
2.) The manufacturer of a sports car claims that the fuel injection system lasts 48 months before it
needs to be replaced. A consumer group tests this claim by surveying a random sample of 10
owners who had the fuel injection system replaced. The ages of the cars at the time of
replacement were (in months):
29
44
47
48
53
46
30
51
42
52
A.) Use your calculator to calculate the mean age of a car when the fuel injection system fails x
and standard deviation s. (Round your answers to four decimal places.)
x =_______ months
s =_______months
B.) What is the level of significance?
C.) What is the value of the sample test statistic? (Round your answer to three decimal places.)
3.) Weatherwise is a magazine published by the American Meteorological Society. One issue gives a
rating system used to classify Nor’easter storms that frequently hit New England and can cause
much damage near the ocean. A severe storm has an average peak wave height of 𝜇 = 16.4 feet
for waves hitting the shore. Suppose that a Nor’easter is in progress at the severe storm class
rating. Peak wave heights are usually measured from land (using binoculars) off fixed cement
piers. Suppose that a reading of 35 waves showed an average wave height of x = 17.3 feet.
Previous studies of severe storms indicate that 𝜎 = 3.5 feet. Does this information suggest that
the storm is (perhaps temporarily) increasing above the severe rating? Use 𝛼 = 0.01.
A.) What is the level of significance?
B.) What is the value of the sample test statistic? (Round your answer to two decimal places.)
5) The Nero Match Company sells matchboxes that are supposed to have an average of 40
matches per box, with 𝜎 = 7. A random sample of 98 matchboxes shows the average number of
matches per box to be 42.8. Using a 1% level of significance, can you say that the average
number of matches per box is more than 40?
A.) What is the level of significance?
B.) What is the value of the sample test statistic? (Round your answer to two decimal places.)