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
gregori [183]
3 years ago
14

In a study to establish the absolute threshold of hearing, 80 male college freshmen were each seated in a soundproof room and a

150 H tone was presented at a large number of stimulus levels in a randomized order. The student was asked to press a button if he detected the tone; the experimenter recorded the lowest stimulus level at which the tone was detected. The mean for the group was 22.2 dB with s = 2.1. Estimate the mean absolute threshold for all college freshmen. dB Calculate the 95% margin of error (in dB). (Round your answer to two decimal places.) dB
Mathematics
1 answer:
Norma-Jean [14]3 years ago
8 0

Answer:

Step-by-step explanation:

Hello!

To study the threshold of hering the researcher took a random sample of 80 male college freshmen.

The students underwent an audiometry test where a tome was played and they had to press a button when they detected it.  The researcher recorded the lowest stimulus level at which the tone was detected obtaining a sample mean of X[bar]= 22.2 dB and a standard deviation of S= 2.1 dB

To estimate the population mean, since we don't have information about the variable distribution but the sample size is greater than 30, you can use the approximation of the standard normal distribution:

X[bar] ± Z_{1-\alpha /2} * \frac{S}{\sqrt{n} }

Where the semiamplitude or margin of error of the interval is:

d= Z_{1-\alpha /2} * \frac{S}{\sqrt{n} }

Using a 95% level Z_{0.975}= 1.965

d= 1.965 * \frac{2.1}{\sqrt{80} }

d= 0.46

The point estimate of the population mean of the threshold of hearing for male college freshmen is X[bar]= 22.2 db

And the estimation using a 95%CI is [21.74;22.66]

I hope this helps!

You might be interested in
Please help me with this asap
Mice21 [21]

Answer:

I think the answer is A

hope this helps :3

sorry if im wrong

5 0
3 years ago
You are designing a rectangular garden. the garden will be enclosed by fencing on three sides and by a house on the fourth side.
RUDIKE [14]
Suppose the dimensions of the rectangle is x by y and let the side enclosed by a house be one of the sides measuring x, then the sides that is to be enclosed are two sides measuring y and one side measuring x.

Thus, the length of fencing needed is given by

P = x + 2y

The area of the rectangle is given by xy,

i.e.

xy = 288  \\  \\  \\  \\ \Rightarrow y= \frac{288}{x}

Substituting for y into the equation for the length of fencing needed, we have

P=x+2\left( \frac{288}{x} \right)=x+ \frac{576}{x}

For the amount of fencing to be minimum, then

\frac{dP}{dx} =0 \\  \\ \Rightarrow1- \frac{576}{x^2} =0 \\  \\ \Rightarrow \frac{576}{x^2} =1 \\  \\ \Rightarrow x^2=576 \\  \\ \Rightarrow x=\sqrt{576}=24

Now, recall that

y= \frac{288}{x} = \frac{288}{24} =12

Thus, the length of fencing needed is given by

P = x + 2y = 24 + 2(12) = 24 + 24 = 48.

Therefore, 48 feets of fencing is needed to enclose the garden.
8 0
3 years ago
In the right -angled tringles began the ABC in the ED :8cm ,and DC :10cm then the length of the air
fgiga [73]
ED:8cm,DC:10 so the air is HD:18
7 0
3 years ago
PLSSS HELPPPP I WILLL GIVE YOU BRAINLIEST!!!!!! PLSSS HELPPPP I WILLL GIVE YOU BRAINLIEST!!!!!! PLSSS HELPPPP I WILLL GIVE YOU B
Marta_Voda [28]

Answer:

x=2

y=-3

Step-by-step explanation:

5 0
2 years ago
Read 2 more answers
Why is the greatest common factors with 2 numbers sometimes 1
OverLord2011 [107]
The greatest common factor of two numbers, one of which is 1, will always be 1.
5 0
2 years ago
Other questions:
  • Solve 3+4n/n = 7b for n
    14·1 answer
  • What is the answer? to this question
    14·1 answer
  • Please help? ill give brainliest too
    13·2 answers
  • Need help solving for A
    13·1 answer
  • a savings account balance is compounded continuously. If the interest rate is 3.1% per year and the current balance is $1077.00,
    10·1 answer
  • The perimeter of a rectangular classroom is 52 feet. If the length is 10 more feet than the width, what is the length?
    12·1 answer
  • Whats the RIGHt answer giving brainliest
    15·1 answer
  • Find the distance between the two points.<br> . (2, 10), (5, -4)
    14·1 answer
  • What is the domain and range for following graph
    5·2 answers
  • Any number which is divisible by both 3 and 5 must…..
    14·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!