In: Statistics and Probability
The Wechsler Adult Intelligence Scale (IQ test) is constructed
so that Full Scale IQ scores follow...
The Wechsler Adult Intelligence Scale (IQ test) is constructed
so that Full Scale IQ scores follow a normal distribution, with a
mean of 100, and a standard deviation of 15. The mayor of Smart
Town believes the county's residents are smarter than the national
average and wants to use it (the intelligence of the residents) as
a marketing tool to bring industries to the area.
A researcher is hired to conduct a study to determine whether
Smart County's residents have, on average, higher Full Scale IQs
than the population. A random sample of 100 people from Smart
County were given the IQ test and were found to have an average
Full Scale IQ of 105. Use α=0.05α=0.05 level of significance.
- Which hypothesis test should be used to determine whether the
mean Full Scale IQ score of the Smart County residents is higher
than the national average?
- z-test for the population mean
- t-test for the population mean
- z-test for the population proportion
- t-test for the population proportion
- What are the null and alternative hypotheses?
- H0: μ = 105; Ha: μ ≠ 105
- H0: μ = 105; Ha: > 105
- H0: μ = 105; Ha: μ ≠ 100
- H0: μ = 100; Ha: > 100
- What is the value of the test statistic used to determine
whether the mean Full Scale IQ score of the Smart County residents
is higher than the national average?
- After analyzing the data to determine whether the mean Full
Scale IQ score of the Smart County residents is higher than the
national average, the P-value of .0004 was obtained.
- Do not reject the null hypothesis. The average Full Scale IQ of
Smart County residents is not higher than the population
average.
- Do not reject the null hypothesis. The average Full Scale IQ of
Smart County residents is higher than the population average.
- Reject the null hypothesis. The average Full Scale IQ of Smart
County residents is not higher than the population average.
- Reject the null hypothesis. The average Full Scale IQ of Smart
County residents is higher than the population average.