Chapter 2, Problem 2PT

To determine

To select: the best answer for the given question.

Answer to Problem 2PT

The standard deviation is 4

Explanation of Solution

Given:

  

  $\begin{array}{r}\hfill \\ \hfill \end{array}$Calculation:

We are given a Normal distribution curve as follows:

  

  $\begin{array}{r}\hfill \\ \hfill \end{array}$

From the above graph, the center value for the graph is 2. It is known that the center for normal curve will be the mean of the corresponding distribution.

Therefore, the mean of the distribution, $\mu =2$

Also, at one standard deviation away from the mean, normal curve has its infection point

From the above graph, at -4 and 6,the cure is changing its direction .In other words ,theinflection points are -4 and 6

That is µ-s=-4 and µ+ s=6

As $\mu =2,$ $[\sigma =4$

Hence, the standard deviation is 4

Conclusion:

Hence, the standard deviation is 4