• 0
Votes
name

A PHP Error was encountered

Severity: Notice

Message: Undefined index: userid

Filename: views/question.php

Line Number: 212

Backtrace:

File: /home/mycocrkc/statisticsanswered.com/application/views/question.php
Line: 212
Function: _error_handler

File: /home/mycocrkc/statisticsanswered.com/application/controllers/Questions.php
Line: 416
Function: view

File: /home/mycocrkc/statisticsanswered.com/index.php
Line: 315
Function: require_once

According to a research institution, men spent an average of $135.95 on Valentine's Day gifts in 2009. Assume the standard deviation for this population is $45 and that it is normally distributed. A random sample of 20 men who celebrate Valentine's Day was selected. Complete parts a through e.

a. Calculate the standard error of the mean.

b. What is the probability that the sample mean will be less than $125?

c. What is the probability that the sample mean will be more than $140?

d. What is the probability that the sample mean will be between $110 and $155?

e. Identify the symmetrical interval that includes 95% of the sample means if the true population mean is $135.95.