(a) True or False, and briefly explain: For a given data set, a 95% confidence interval is longer than a 90% interval. (b) In this course we have considered confidence intervals for an unknown...

Extracted text: (a) True or False, and briefly explain: For a given data set, a 95% confidence interval is longer than a 90% interval. (b) In this course we have considered confidence intervals for an unknown parameter, 0, to be of the form: Ô + (CF)SE(@), CF= confidence factor. True or False, and briefly explain: The endpoints of these confidence intervals are random vari- ables. (c) A real estate office conducts a survey in a certain town to determine how far the head of household has to commute to work. A random sample of 1000 households is chosen and it is found that on average the heads of the sample households commuted 8.7 miles to work; the sample SD of the distances was 9.0 miles. All distances are one-way; if someone isn't working the commute distance is defined to be 0. Someone determines the following confidence interval: 8.7±2(-). Can you explain what the interval is for or do you need more information to answer the question?