1. State whether the standardized test statistic t indicates that you should reject the null hypothesis. Explain.
?(a) t=2.201
?(b) t=0
?(c) t=-2.089
?(d) t-2.237
(*****t0 on the graph is positioned to the left at -2.108****)
2.In a survey of 628 males ages? 18-64, 393 say they have gone to the dentist in the past year.
Construct? 90% and? 95% confidence intervals for the population proportion. Interpret the results and compare the widths of the confidence intervals.
3.In a random sample of 21 ?people, the mean commute time to work was 31.8 minutes and the standard deviation was 7.3 minutes. Assume the population is normally distributed and use a? t-distribution to construct a 90?% confidence interval for the population mean μ. What is the margin of error of mμ??