a) American households spent an average of about $44 in 2007 on Halloween merchandise such as costumes, decorations and candy. To see if this number had changed, researchers conducted a new survey in 2008 before industry numbers were reported. The survey included 2100 households and found that average Halloween spending was $52 per household.
The sample mean is_____
dollars, while the claimed population mean is ______
dollars.


b) The average GPA of students in 2001 at a private university was 3.56. A survey on a sample of 350 students from this university yielded an average GPA of 3.42 in Spring semester of 2012.
The sample mean is ______
and the claimed population mean is ______

Respuesta :

A)

The sample mean is  52

The claimed population mean is 44

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The sample mean is the mean found in the survey (of the sample of people). The sample mean is found by adding up the values and dividing by the sample size n. The larger n gets, the closer the sample mean should get to the population mean. This is assuming the sample is random and representative of the population.

The population mean is a claim made by another study/survey/etc. Usually generalized statements such as "Americans spent an average of X dollars (in year Y)" would have X be considered the population mean.

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B)

Sample mean is 3.42

Claimed population mean is 3.56

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Same idea as part A, but we're using different numbers and a different problem context.

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Note: The year numbers and the sample sizes are not used to answer any of the four questions above.

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