FieniChoonin

Answered 2021-07-04
Author has **23752** answers

asked 2021-02-21

Express your answer in the form of three inequalities. Give your answers in decimal fractions up to three places \(\displaystyle<{p}<\) Express the same answer using a point estimate and a margin of error. Give your answers as decimals, to three places.

\(\displaystyle{p}=\pm\)

asked 2021-06-08

When \(\displaystyle\sigma\) is unknown and the sample is of size \(\displaystyle{n}\geq{30}\), there are two methods for computing confidence intervals for \(\mu\). 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 \(\displaystyle\sigma\), 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 \(\displaystyle\sigma\). 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 \(\displaystyle\overline{{{x}}}={45.2}\) and sample standard deviation s=5.3. Compute 90%, 95%, and 99% confidence intervals for \(\displaystyle\mu\) using Method 2 with the standard normal distribution. Use s as an estimate for \(\displaystyle\sigma\). Round endpoints to two digits after the decimal.

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 2021-05-26

You are given the sample mean and the population standard deviation. Use this information to construct 90% and 95% confidence intervals for the population mean. Interpret the results and compare the widths of the confidence intervals. From a random sample of 36 business days from February 24, 2016, through February 24, 2017, the mean closing price of Apple stock was $116.16. Assume the population standard deviation is $10.27.

asked 2021-08-03

Give your answer to three decimals.

\(< p <\)

asked 2020-10-25