1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Anvisha [2.4K]
3 years ago
9

An advertising agency that serves a major radio station wants to estimate the mean amount of time the station’s audience members

listen to the radio on a daily basis. From past studies the population standard deviation is known to equal 45 minutes. What sample size is needed if the agency wants to be 90% confident of being within (±) 5 minutes of the true mean amount of time audience members listen to the radio per day?
Mathematics
2 answers:
Anvisha [2.4K]3 years ago
6 0

Answer:

The margin of error for the true mean is :

ME=z_{\alpha/2}\frac{\sigma}{\sqrt{n}}

n=(\frac{1.645(45)}{5})^2 \\\\=219.18\\\\ \approx 220

Therefore, the answer for this case would be n = 220

Step-by-step explanation:

Population standard deviation is 45

Margin of error is 5

|Z(0.05)|=1.645 (check standard normal table)

The margin of error for the true mean is :

ME=z_{\alpha/2}\frac{\sigma}{\sqrt{n}}

n=(\frac{1.645(45)}{5})^2 \\\\=219.18\\\\ \approx 220

Therefore, the answer for this case would be n = 220

Flura [38]3 years ago
5 0

Answer:

n=(\frac{1.645(45)}{5})^2 =219.18 \approx 220

So the answer for this case would be n=220 rounded up to the nearest integer

Step-by-step explanation:

Information given

\sigma = 45 represent the population deviation

ME = 5 represent the margin of error

The margin of error for the true mean is given by this formula:

ME=z_{\alpha/2}\frac{\sigma}{\sqrt{n}}    (a)

And on this case we have that ME =5 and we are interested in order to find the value of n, if we solve n from equation (4) we got:

n=(\frac{z_{\alpha/2} \sigma}{ME})^2   (b)

The critical value for 90% of confidence interval now can be founded using the normal distribution. The significance level is \alpha=1-0.9=0.1 and the critical value would be z_{\alpha/2}=1.645, replacing into formula (b) we got:

n=(\frac{1.645(45)}{5})^2 =219.18 \approx 220

So the answer for this case would be n=220 rounded up to the nearest integer

You might be interested in
What is the gcf of 18 and 9?
Zanzabum
The gcf of 9 and 18 is 18
8 0
3 years ago
Read 2 more answers
Mrs. Simmons gave a history test worth 92 points. There were only two types of questions on it: 2-point true/false questions and
SVETLANKA909090 [29]

Answer:

There are 8 true/false questions and 26  fill-in-the-blank questions.

Step-by-step explanation:

Let "t" be the number of 2-point true/false questions and "f" the number of 5-point fill-in-the-blank questions.

Mrs. Simmons gave a history test worth 92 points. Symbollically,

2 t + 5 f = 92   [1]

There were a total of 34 questions in the test. Symbollicaly,

t + f = 34

t = 34 - f   [2]

If we replace [2] in 1, we get

2 (34 - f) + 5 f = 92

68 - 2 f + 5 f = 92

3 f = 24

f = 8

We replace f = 8 in [2],

t = 34 - 8 = 26

There are 8 true/false questions and 26  fill-in-the-blank questions.

7 0
3 years ago
Can someone help me find the measure of each angle indicated please
Lyrx [107]

Answer:

Option B, 105 would be correct

Step-by-step explanation:

The Vertical Angles Theorem states that angles that are opposite diagonally are congruent, therefore; ? = 105°

Hope this helps!

5 0
2 years ago
Write an inequality to describe the region represented on the number line.
vovangra [49]

Answer:

See explanation

Step-by-step explanation:

The question is incomplete, as the required number line is not included in the question.

A general explanation is as follows:

An open circle means > or <

A closed circle means >= or <=

Take, for instance, the attached number line:

The open dot on -3 means >-3 or <-3

The arrow points to the right direction, means >-3 i.e. greater than -3

Hence, the inequality is:

x > -3

7 0
3 years ago
Fill the chart for me
yulyashka [42]
6, 1.5, 10, 16, 80, and 2
4 0
3 years ago
Other questions:
  • How do you know w/o calculator? PLZZZZZ HELPPPPPPPPPp
    15·1 answer
  • Olive walks at a rate of 4 miles per hour. She lives 2 miles from the new station. How long will it take her or walk home from t
    12·2 answers
  • What is the value of n so that the expression x^2 + 11x + n is a perfect trinomial?
    11·1 answer
  • Compare the functions below: f(x) = −3 sin(x − π) + 2
    15·2 answers
  • Use the Laplace transform to solve the given initial-value problem. Use the table of Laplace transforms in Appendix III as neede
    13·1 answer
  • Imari went on a hike and recorded the number of each type of bird he saw. The circle graph shows the results of his count. Imari
    10·2 answers
  • If a line with a slope of -2 crosses the y-axis at (0,3). What is the equation of the line?
    11·1 answer
  • I don’t understand this at all...can someone give me the answer or help me figure it out!?
    8·1 answer
  • Is the equation y = x^2 -6 linear?
    12·2 answers
  • SOMEONE PLEASE HELP ME
    9·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!