Chapter PIV, Problem 27RE

(a)

To determine

To Find: how long you can afford to stay in Kyrgyzstan, on average.

Answer to Problem 27RE

21 days

Explanation of Solution

Given:

It could be predicted to spend approximately 4237 some every day.

Formula used:

  $E\left(nX\right)=nE\left(X\right)$

Calculation:

budget makes it possible to invest 90000.

Let's assume you should stay for 'n' days, suppose.

Let the amount spent on each day be X.

  $\begin{array}{c}E\left(nX\right)=nE\left(X\right)\\ nE\left(X\right)=90000\\ n\left(4237\right)=2\left(13.50\right)\end{array}$

  $\begin{array}{c}n=\frac{90000}{4237}\\ =21.24\\ =21day\end{array}$

It can stay for 21 days.

(b)

To determine

To find: the standard deviation of expenses for the trip of that duration.

Answer to Problem 27RE

7560

Explanation of Solution

Formula used:

  $SD\left(21X\right)=21SD\left(X\right)$

Calculation:

Standard deviation is

  $\begin{array}{c}SD\left(21X\right)=21SD\left(X\right)\\ =21\left(360\right)\\ =7560som\end{array}$

(c)

To determine

To find: how much extra cash you might bring on average, how much a "cushion" would have every day.

Answer to Problem 27RE

34.29

Explanation of Solution

Let the total expenditure be T.

Y is the expectation of

T-Y > 2SD

T-Y > 2(360)

>720som

So we need to bring 720som more.

The cushion there would have per day is $\frac{720}{21}=34.29som$