91影视

Solar energy generation along highways. Refer to the International Journal of Energy and Environmental Engineering (December 2013) study of solar energy generation along highways, Exercise 8.39 (p. 481). Recall that the researchers compared the mean monthly amount of solar energy generated by east-west鈥� and north-south鈥� oriented solar panels using a matched-pairs experiment. However, a small sample of only five months was used for the analysis. How many more months would need to be selected to estimate the difference in means to within 25 kilowatt-hours with a 90% confidence interval? Use the information provided in the SOLAR file to find an estimate of the standard error required to carry out the calculation

Step by step solution

01

Given Information

With a 90% confidence interval, the researchers compared the mean monthly amount of solar energy.

The standard error is 86.4.

The sampling error is 25.

02

Z-value

A minimum of two steps are required.

For $伪=0.1$

The z-value is given by

$$\begin{gathered} z_{\frac{伪}{2}}=z_{0.05} \\ =1.645 \end{gathered}$$

03

Compute the sample

For, $z=1.645,鈥�andSE=86.4$

The sample is calculated as

$$\begin{gathered} n_d={\left\{\frac{z_{\frac{伪}{2}}\left({蟽}_d\right)}{SE}\right\}}^2 \\ ={\left\{\frac{1.645脳86.4}{25}\right\}}^2 \\ ={\left\{\frac{142.128}{25}\right\}}^2 \\ ={\left\{5.685\right\}}^2 \\ =32.319 \\ =33 \end{gathered}$$

A small sample of only 5 months used for analysis.

Therefore,

$33-5=28$

Therefore, 28 months would need to estimate the difference in means to within 25 kilowatt hours.

Unlock Step-by-Step Solutions & Ace Your Exams!

• Full Textbook Solutions

  Get detailed explanations and key concepts

• Unlimited Al creation

  Al flashcards, explanations, exams and more...

• Ads-free access

  To over 500 millions flashcards

• Money-back guarantee

  We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91影视!