The metric system uses units such as meter, liter, and gram to measure length, liquid volume, and mass, just as the U.S. customary system uses feet, quarts, and ounces to measure these.

8 0

3 years ago

A designer wants to create a whisper chamber in the shape of an ellipse. He has a warehouse space with a longest length of 50 ya

Zanzabum

Answer:

22.9 yards

Step-by-step explanation:

Since b² = a² - c² where a = vertex of major axis, 2a = 50 yards the length of the major axis. So , a = 50/2 = 25 yards. c = focus of chamber = 10 yards from center and b = vertex of minor axis.

So, b = ±√(a² - c²)

= ±√(25² - 10²)

= ±√(625 - 100)

= ±√525

= ±22.91 yards

≅ ± 22.9 yards

Since b = length of minor axis from center of chamber = 22.91 yards. So, he should build the whisper chamber 22.9 yards out from the center of the chamber.

7 0

3 years ago

A recent national survey found that high school students watched an average (mean) of 7.8 movies per month with a population sta

notka56 [123]

Answer:

Step-by-step explanation:

Given that :

Mean = 7.8

Standard deviation = 0.5

sample size = 30

Sample mean = 7.3 5.4772

The null and the alternative hypothesis is as follows;

$\mathbf{ H_o: \mu \geq 7.8}$

$\mathbf{ H_1: \mu < 7.8}$

The test statistics can be computed as :

$z = \dfrac{X- \mu}{\dfrac{\sigma}{\sqrt{n}}}$

$z = \dfrac{7.3- 7.8}{\dfrac{0.5}{\sqrt{30}}}$

$z = \dfrac{-0.5}{\dfrac{0.5}{5.4772}}$

$z = - 5.4772$

The p-value at 0.05 significance level is:

p-value = 1- P( Z < -5.4772)

p value = 0.00001

Decision Rule:

The decision rule is to reject the null hypothesis if p value is less than 0.05

Conclusion:

At the 0.05 significance level, there is sufficient information to reject the null hypothesis. Therefore ,we conclude that college students watch fewer movies a month than high school students.

8 0

3 years ago