A past study claimed that adults in America spent an average of 18 hours a week on leisure activities. A researcher wanted to test this claim. She took a sample of 10 adults and asked them about the time they spend per week on leisure activities. Their responses (in hours) are as follows.
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Assume that the times spent on leisure activities by all adults are normally distributed. Using the 5% significance level, can you conclude that the average amount of time spent by American adults on leisure activities has changed? (Hint: First calculate the sample mean and the sample standard deviation for these data. Then make the test of hypothesis about μ.)
Round the sample standard deviation to three decimal places.
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