asked 2021-08-08

A) Read carefully the text and provide each of the following:

The sample size \(\displaystyle?=\)

from the sample, the number of college students who own a car is \(\displaystyle?=\)

the confidence level is \(\displaystyle{C}{L}=\) \(\displaystyle\%\).

B) Find the sample proportion \(\displaystyle\hat{{?}}=\)

and \(\displaystyle\hat{{?}}={1}−\hat{{?}}=\)

asked 2021-06-01

Suppose that you take 500 simple random samples from a population and that, for each sample, you obtain a 90% confidence interval for an unknown parameter. Approximately how many of those confidence intervals will not contain the value of the unknown parameter?

asked 2021-06-24

asked 2021-05-14

When σ is unknown and the sample size is \(\displaystyle{n}\geq{30}\), there are tow methods for computing confidence intervals for μμ. Method 1: Use the Student's t distribution with d.f. = n - 1. This is the method used in the text. It is widely employed in statistical studies. Also, most statistical software packages use this method. Method 2: When \(\displaystyle{n}\geq{30}\), use the sample standard deviation s as an estimate for σσ, and then use the standard normal distribution. This method is based on the fact that for large samples, s is a fairly good approximation for σσ. Also, for large n, the critical values for the Student's t distribution approach those of the standard normal distribution. Consider a random sample of size n = 31, with sample mean x¯=45.2 and sample standard deviation s = 5.3. (c) Compare intervals for the two methods. Would you say that confidence intervals using a Student's t distribution are more conservative in the sense that they tend to be longer than intervals based on the standard normal distribution?

asked 2021-05-05

asked 2021-08-10

Choose 2 answers in nearest unit (ones) or in whole number.

Example, if your answer is \(\displaystyle{888.83}\leq\mu\leq{899.56}\), choose 889 and 900.

\(\begin{array}{|c|c|}\hline 775 & 773 & 807 & 797 & 791 & 769 & 789 & 768 & 805 & 763 & 771 & 792 \\ \hline \end{array}\)

asked 2021-05-09

a. What is the value of the sample mean resonance frequency?

b. The confidence level for one of these intervals is 90%90%and for the other it is 99%99%. Which is which, and how can you tell?