Chapter 14.4, Problem 8CFU

(a)

To determine

To draw:

The graph of a curve that represents the frequency distribution.

Explanation of Solution

Given:

Normally distributed data is $=73$

Standard deviation $=3$

Concept used:

Normal distribution: - A normal distribution is a frequency distribution that often occurs

There is a large number of values in a set of data.

The graph of this distribution is a symmetric, bell-shaped curve.

Calculation:

Normally distributed data is $=73$

Standard deviation $=3$

  $\sigma =3$

Draw the graph of the frequency distribution

  

A normally distributed data set is centered on the mean /median /mode and symmetric about this point.

This graph is bell curve.

The standard deviation is a rough measure of the spread.

(b)

To determine

To draw:

The graph of a curve that represents the frequency distribution.

Explanation of Solution

Given:

Normally distributed data is $=73$

Standard deviation $=3$

Concept used:

Normal distribution: - A normal distribution is a frequency distribution that often occurs

There is a large number of values in a set of data.

The graph of this distribution is a symmetric, bell-shaped curve.

Calculation:

Normally distributed data is $=73$

Standard deviation $=3$

  $\sigma =3$

Draw the graph of the frequency distribution

  

A normally distributed data set is centered on the mean /median /mode and symmetric about this point.

This graph is bell curve.

The standard deviation is a rough measure of the spread.

(c)

To determine

To find:

The interval about the mean that includes $99.7\%$ of the data.

Answer to Problem 8CFU

Chemistry

Explanation of Solution

Given:

Normally distributed data is $=73$

Standard deviation $=3$

Concept used:

Normal distribution: - A normal distribution is a frequency distribution that often occurs

There is a large number of values in a set of data.

The graph of this distribution is a symmetric, bell-shaped curve.

Calculation:

Normally distributed data is $=73$

Standard deviation $=3$

  $\sigma =3$

A normally distributed data set is centered on the mean /median /mode and symmetric about this point.

This graph is bell curve.

The standard deviation is a rough measure of the spread.

Chemistry was $3$ standard deviations above the mean (chemistry scored $82$ the mean was $73$ and the SD was $3$ .Salali’s $9$ points above the mean which is equivalent to $3$ times the standard deviation) in comparison performance in speech was only $2$ standard deviations above the mean.