A Random Sample of 121 Checking Accounts at a Bank

question 28

Essay

A random sample of 121 checking accounts at a bank showed an average daily balance of $280. The standard deviation of the population is known to be $66.
a.Is it necessary to know anything about the shape of the distribution of the account balances in order to make an interval estimate of the mean of all the account balances? Explain.
b.Find the standard error of the mean.
c.Give a point estimate of the population mean.
d.Construct a 80% confidence interval estimates for the mean.
e.Construct a 95% confidence interval for the mean.

Identify components of a measure, including true score and measurement error.

Understand the role of validity in measuring behavior and its types.

Appreciate the interrelation between reliability and validity in the context of research methods.

Grasp the use of Pearson product-moment correlation coefficient in reliability and validity assessments.

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Definitions:

Irritable

Easily annoyed or angered, often displaying a tendency to be upset by minor disturbances or inconveniences.

Aerobic Exercise

Physical activity that relies on the oxygen to generate energy, improving cardiovascular conditioning.

Life Expectancy

The average period that an individual is expected to live as determined by statistical analysis, often influenced by factors such as genetics, lifestyle, and healthcare quality.

Sympathetic Nervous System

Part of the autonomic nervous system that prepares the body for rapid response to stressful or emergency situations by activating the fight-or-flight response.