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According to a Recent Survey, Women Chat on Their Mobile

question 71

Short Answer

According to a recent survey, women chat on their mobile phones more than do men (CNN.com, August 25, 2010). Irina wants to estimate the difference between the average chat time for female and male college students. She takes a random sample of 40 male students and 40 female students in her college. She finds that female students chatted for a sample average of 820 minutes per month with a sample standard deviation of 160 minutes. Male students, on the other hand, chatted for a sample average of 760 minutes per month with a sample standard deviation of 240 minutes. You may assume that the population variances are equal.
A) Construct a 95% confidence interval for the difference between the population means.
B) Can we conclude that average chat time is different between female and male college students with 95% confidence?

Definitions:

Balance

The ability to maintain the body's center of mass over its base of support, a key component of physical stability and coordination.

Musculoskeletal Risk Factors

Elements or conditions that increase the likelihood of injury or disease affecting the body's musculoskeletal system, including bones, muscles, and joints.

Mechanical Lift

A device used to assist in the lifting and moving of patients or heavy objects, reducing the risk of injury.

Transfer Roller Sheet

A device made out of fabric designed to help safely move or transfer patients from one surface to another with minimal physical strain.