If the ratio of the width to the length is 1 : 2 then, we can represent their respective lengths using x and 2x.

Width = x
Length = 2x

2(x) + 2(2x) = 324
2x + 4x = 324
6x = 324
x = 54
2x = 108

The width is 54 ft. and the length is 108 feet. Hope this helps!

8 0

3 years ago

Randomly selected students participated in an experiment to test their ability to determine when one minute (or sixty seconds)

zalisa [80]

Answer: $(57.41,\ 62.19)$

Step-by-step explanation:

Given : Sample size : $n=40$

Sample mean : $\overline{x}=59.8\text{ seconds}$

Standard deviation : $\sigma =9.2\text{ seconds}$

Significance level : $\alpha=1-0.9=0.1$

Critical value : $z_{\alpha/2}=1.645$

Formula to find the confidence interval for population mean :-

$\overline{x}\pm z_{\alpha/2}\dfrac{\sigma}{\sqrt{n}}\\\\=59.8\pm(1.645)\dfrac{9.2}{\sqrt{40}}\\\\\approx59.8\pm2.39\\\\=(59.8-2.39,\ 59.8+2.39)\\\\=(57.41,\ 62.19)$

Hence, a 90% confidence interval estimate of the population mean of all students = $(57.41,\ 62.19)$

6 0

3 years ago