21.
Flawed; interpretation implies that the population mean varies rather than the interval
Correct
Flawed; interpretation makes an implication on the individuals rather than the mean.
flawed; intepretation should be about the mean number of hours by adult americans not adults in idaho.
23. we are 90% confident that the mean time in the drive through service of taco bell will be between 161.5 and 164.7 seconds.
25. 1. The sample size should be bigger; 2. decrease the confidence level
31.
Point estimate for population mean = 4.893
95% confident that the mean ph is between 4.690 and 5.096
99% confident that mean ph is between 4.607 and 5.179
margin of error increases as the confidence level increases
32.
Point estimate for population mean = 83.35
95% confidence interval suggests that the travel tax will range between 73.046 and 93.65
decrease the margin of error as the confidence interval becomes narrow thus, increases precision
33.
95% confident mean repair cost for low-impact collision is between $1035.8 and $ 2477.2
The confidence interval will possibly be narrower because there is les variability in data since, variability in terms of producer of the vehilce is removed.