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
spin [16.1K]
3 years ago
12

Q1. (10 points) Suppose we want to estimate the average weight of an adult male in Dekalb County, Georgia. We draw a random samp

le of 1,000 men and weigh them. We find that the average in our sample weighs 180 pounds, and the standard deviation of the sample is 35 pounds. a) Construct a 99% confidence interval for the population mean. b) Interpret your conclusion
Mathematics
1 answer:
netineya [11]3 years ago
8 0

Answer:

a) The 99% confidence interval would be given by (177.144;182.856)

b) We are 99% confident that the true mean for the weight of an adult male in Dekalb County, Georgia is between 177.144 and 182.856.

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

\bar X=180 represent the sample mean

\mu population mean (variable of interest)

s=35 represent the sample standard deviation

n=1000 represent the sample size  

Part a: Confidence interval

The confidence interval for the mean is given by the following formula:

\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}   (1)

In order to calculate the critical value t_{\alpha/2} we need to find first the degrees of freedom, given by:

df=n-1=1000-1=999

Since the Confidence is 0.99 or 99%, the value of \alpha=0.01 and \alpha/2 =0.005, and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-T.INV(0.005,999)".And we see that t_{\alpha/2}=2.58

Now we have everything in order to replace into formula (1):

180-2.58\frac{35}{\sqrt{1000}}=177.144    

180+2.58\frac{35}{\sqrt{1000}}=182.856    

So on this case the 99% confidence interval would be given by (177.144;182.856)    

Part b

We are 99% confident that the true mean for the weight of an adult male in Dekalb County, Georgia is between 177.144 and 182.856.

You might be interested in
Write the point-slope form of the equation for a line that passes through (6, -1) with a slope of 2.
Naddika [18.5K]

Answer:

2x-y-13=0

Step-by-step explanation:

6 0
3 years ago
Robert climbed 755 steps in 12 1/2 minutes how many steps did he average per minute
Liula [17]
Basically, you have to do 755/12.5 That will give you your average per minute.
6 0
3 years ago
Read 2 more answers
Which expression is equivalent to 3^8 times 3^7?
m_a_m_a [10]

Answer:

1/3⁵⁶ is the answer i think if it's not then i am sorry

5 0
2 years ago
A square field has an area of 100 square meters. What is the length of the square? Show how you got the work please.
Goryan [66]

Answer:

The length of the square is 10 meters.

Step-by-step explanation:

First, you need to know that a square has four equal sides, and that finding the area of a square means multiplying one side by another side. This means that if you know the area of the square, all you have to do is find the square root of the area to find a side length. So, by using a calculator, you can find that the square root of 100 is 10, which is the length of one side of the square.


8 0
3 years ago
Read 2 more answers
(-6+7) - (-4x - 2) ?
Law Incorporation [45]

the answer to your question is 7

6 0
3 years ago
Read 2 more answers
Other questions:
  • How to write 5x923 in expanded form
    7·2 answers
  • the lateral area of a cone is 574 pi cm2. The radius is 19.6 cm. What is the slant height to the nearest tenth of a centimeter?
    7·2 answers
  • Simplify (9^2/3*9^4/2)/9^1/2
    15·1 answer
  • Helppp please and thanks
    5·1 answer
  • What is the equation if this line? (3,6) (-3,-6)
    6·1 answer
  • Joey spins a spinner and lands on the number 4. Then Jennifer spins and lands on the number 2. Are these events independent or d
    8·1 answer
  • What is tan E? Give your answer as a simplified fraction.
    11·1 answer
  • 3-2+x+ 436 123/157 =
    7·2 answers
  • Math need help please
    10·1 answer
  • If jummai is 12years old and Tunde is 8years old and they share 15bananas in the ratio of their ages how many will each have sho
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!