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
Marina CMI [18]
3 years ago
9

Assume that the salaries of elementary school teachers in the united states are normally distributed with a mean of $32,000 and

a standard deviation of $3000. if 100 teachers are randomly selected, find the probability that their mean salary is less than $32,500.
Mathematics
2 answers:
murzikaleks [220]3 years ago
8 0

Answer: 0.9525

Step-by-step explanation:

Given : The salaries of elementary school teachers in the united states are normally distributed with a mean of \mu=\$32,000 and a standard deviation of \sigma=\$3000.

Sample size : n= 100

Let x be a random variable that denotes the salaries of elementary school teachers in the united states.

Formula : z=\dfrac{x-\mu}{\dfrac{\sigma}{\sqrt{n}}}

Then, the probability that their mean salary is less than $32,500 will be :-

P(x

Hence, the probability that their mean salary is less than $32,500 = 0.9525

yanalaym [24]3 years ago
7 0
Can you make this question clearer to read
You might be interested in
What does 8.1 pi belong to other than irrational?
kvv77 [185]
Real numbers, both rational and irrational numbers are real numbers
5 0
3 years ago
Read 2 more answers
Convert 25% to a decimal.
LekaFEV [45]
Your answer is C.

Hope this helped.
5 0
3 years ago
Read 2 more answers
The brand manager for a brand of toothpaste must plan a campaign designed to increase brand recognition. He wants to first deter
VMariaS [17]

Answer:

He must survey 123 adults.

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of \pi, and a confidence level of 1-\alpha, we have the following confidence interval of proportions.

\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}

In which

z is the z-score that has a p-value of 1 - \frac{\alpha}{2}.

The margin of error is:

M = z\sqrt{\frac{\pi(1-\pi)}{n}}

Assume that a recent survey suggests that about 87​% of adults have heard of the brand.

This means that \pi = 0.87

90% confidence level

So \alpha = 0.1, z is the value of Z that has a p-value of 1 - \frac{0.1}{2} = 0.95, so Z = 1.645.

How many adults must he survey in order to be 90​% confident that his estimate is within five percentage points of the true population​ percentage?

This is n for which M = 0.05. So

M = z\sqrt{\frac{\pi(1-\pi)}{n}}

0.05 = 1.645\sqrt{\frac{0.87*0.13}{n}}

0.05\sqrt{n} = 1.645\sqrt{0.87*0.13}

\sqrt{n} = \frac{1.645\sqrt{0.87*0.13}}{0.05}

(\sqrt{n})^2 = (\frac{1.645\sqrt{0.87*0.13}}{0.05})^2

n = 122.4

Rounding up:

He must survey 123 adults.

6 0
3 years ago
Please help!!! Mark is learning to snowboard. The club charges $10 per hour for snowboard lessons and $40 for the lift ticket an
sveta [45]
H represents the number of hours:
10h + 40
(40 represents, well $40)
4 0
3 years ago
Read 2 more answers
A hot air balloon is descending
Harlamova29_29 [7]

Answer:

54 3/4

Step-by-step explanation:

18*3=54

1/4*3=3/4

6 0
3 years ago
Other questions:
  • How do you do this type of exponent? Problem: x • x • x • x • ... • x ; I really don't get this and need help! Thanks.
    10·1 answer
  • Which statements about doubling an investment are true? Check all that apply.
    10·2 answers
  • PLEASE HELP!!!!!!!!!!!!!!!!!!!!!!!
    8·1 answer
  • Solve this equation, and show work. worth 40 points.
    8·1 answer
  • 965000000000000 in scientific notation
    10·2 answers
  • 1.23 x 1.1 equals =
    15·1 answer
  • What is the answer to 4x-3=37
    5·2 answers
  • R is a three digit number determine the digits of r from the clues the first digit is the answer when the third digit is divided
    7·1 answer
  • Mr jacob has 4 white beans and 8 black beans what is thr frction of the black beans 1/3 4/8 8/4 2/3
    10·2 answers
  • What is the value of x when h(x) = −3?
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!