Download A consumer advocacy group suspects that a local supermarket`s 10

A consumer advocacy group suspects that a local supermarket’s 10-ounce packages of
cheddar cheese actually weigh less than 10 ounces (on the average). The group took a
random sample of 26 such packages and found that the mean weight for the sample was
9.955 ounces with a standard deviation of .15 ounce.
Hypotheses:
Test statistic: _____________ d.f.________ p-Value:___________
Reject or Fail to Reject?
Conclusions: We do/don’t have sufficient evidence to conclude that the mean
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According to a survey conducted by the National Retail Association, the average amount that
households in the United States planned to spend on gifts, decorations, greeting cards, and food
during the 2015 holiday season was $1040. Suppose that a recent random sample of 24
households showed that they plan to spend an average of $1105 on such items during this year’s
holiday season with a standard deviation of $230. Test at the 1% significance level whether the
mean of holiday-related expenditures for this year exceed $1040.
Hypotheses:
Test statistic: _____________ d.f.________ p-Value:___________
Reject or Fail to Reject?
Conclusions: We do/don’t have sufficient evidence to conclude that the mean
________________________________________________________________
According to the Bureau of Labor Statistics, there were 8.1 million unemployed people in August
2015. The average duration of unemployment for these people was 16.3 weeks (Bureau of Labor
Statistics News). Suppose that a recent random sample of 14 unemployed Americans resulted in a
mean duration of unemployment of 16.9 weeks with a standard deviation of 4.2 weeks. Test at the
2% significance level whether the current mean duration of unemployment for all unemployed
exceeds 16.3 weeks.
Hypotheses:
Test statistic: _____________ d.f.________ p-Value:___________
Reject or Fail to Reject?
Conclusions: We do/don’t have sufficient evidence to conclude that the mean
________________________________________________________________
According to the NCAA, the mean height of all female college basketball players in 2015 was
69.5 inches. A random sample of 25 players produced a mean height of 70.25 inches with a
standard deviation of 2.1 inches. Assume the heights of female college basketball players are
normally distributed. Test at the 1% significance level whether their mean height exceeds 69.5
inches.
Hypotheses:
Test statistic: _____________ d.f.________ p-Value:___________
Reject or Fail to Reject?
According to Money magazine, the average cost of a visit to a doctor’s office in the United States
was $90 in 2014. Suppose that a recent random sample of 25 visits to doctors gave a mean of
$96.50 and a standard deviation of $2.70. Using the 5% significance level, can you conclude that
the current mean cost of a visit to a doctor’s office exceeds $90? (Assume that such costs for all
visits to doctors are normally distributed so that the t-distribution applies.)
Hypotheses:
Test statistic: _____________ d.f.________ p-Value:___________
Reject or Fail to Reject?
Grand Auto Corporation produces auto batteries. The company claims that its top-of-the-line
Never Die batteries are good, on average, for at least 65 months. A consumer protection agency
tested 15 such batteries to check this claim. It found the mean life of these 15 batteries to be 63
months with a standard deviation of 2 months. At the 5% significance level, test the company’s
claim.
Hypotheses:
Test statistic: _____________ d.f.________ p-Value:___________
Reject or Fail to Reject?