PLEASE HELP ASAP<br><br> 3/10/p=4/5/1/4

SCCoast, an Internet provider in the Southeast, developed the following frequency distribution on the age of Internet users. Fin

Tomtit [17]

Answer:

Mean: 40.17 years.

Standard deviation: 10.97 years.

Step-by-step explanation:

The frequency distribution is in the attached image.

We can calculate the mean adding the multiplication of midpoints of each class and frequency, and dividing by the sample size.

The midpoints of a class is calculated as the average of the bounds of the class.

Then, the mean can be written as:

$E(X)=\dfrac{1}{N}\sum f_iX_i\\\\\\E(X)=\dfrac{1}{60}(3\cdot15+7\cdot25+18\cdot35+20\cdot45+12\cdot 55)=\dfrac{45+175+630+900+660}{60}\\\\\\E(X)=\dfrac{2,410}{60}=40.17$

The standard deviation can be calculated as:

$s=\sqrt{\dfrac{1}{N-1}\sum f_i(X_i-E(X))^2}\\\\\\s=\sqrt{\dfrac{1}{59}[3(15-40.17)^2+7(25-40.17)^2+18(35-40.17)^2+20(45-40.17)^2+12(55-40.17)^2]}$

$\\\\\\s=\sqrt{\dfrac{1}{59}( 1,900.59 + 1,610.90 + 481.12 + 466.58 + 2,639.15 )}\\\\\\s=\sqrt{\dfrac{ 7,098.33 }{59}}=\sqrt{120}=10.97$

4 0

3 years ago

if the population of a country increases by 35% every decade by what percentage does it increase by every year

VikaD [51]

Answer:

hi

have a good day for you

7 0

3 years ago

PLZ HELP ME IN THIS I NEED IT RIGHT AWAY!! ILL GIVE EXTRA POINTS AND BRAINLIST!!!

aniked [119]

Answer: 20

Step-by-step explanation:

So what I did was divide the pages by the hours and got 20

but, when it starts with 20 pages an hour you have... 20

7 0

2 years ago

Suppose a researcher is conducting a hypothesis test for a mean and finds a test statistic of z=2.3z=2.3 . Which of the choices

Galina-37 [17]

Answer:

Option c. The result is significant at the 0.020.02 level.

Step-by-step explanation:

We are given the following in the question:

We are conducting a one tailed hypothesis test with alternate hypothesis

$H_A: \mu > \mu_0$

The z test calculated for the same is

z=2.3

We calculate the p-value from the standard normal table.

p value = 0.010724 at 0.05 significance level.

The result is significant

p value = 0.010724 at 0.01 significance level.

The result is not significant

p value = 0.010724 at 0.02 significance level.

The result is significant at 0.02 significance level.

Thus, the correct answer is

Option c. The result is significant at the 0.020.02 level.

3 0

3 years ago

A children's roller coaster is limited to riders whose height is at least 30 inches and at most 48 inches. Write two inequalitie

SVETLANKA909090 [29]

Answer:

h≤48 h≥30

Step-by-step explanation:

5 0

3 years ago

PLEASE HELP ASAP 3/10/p=4/5/1/4