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
Natalka [10]
3 years ago
8

To get an estimate of consumer spending over a holiday season in 2009, 436 randomly sampled American adults were surveyed. Their

spending for the six-day period after Thanksgiving, spanning the Black Friday weekend and Cyber Monday, averaged $84.71. A 95% confidence interval based on this sample is ($80.31, $89.11). Which of the following statements are true? Select all that apply. A 90% confidence interval would be narrower than the 95% confidence interval if we don't need to be as sure about our estimate. In order to decrease the margin of error of a 95% confidence interval to a third of what is is now, we would need to use a sample 3 times larger. This confidence interval is not valid since the distribution of spending in the sample data is right skewed. The margin of error is $4.4. We are 95% confident that the average spending of these 435 American adults over this holiday season is between $80.31 and $89.11. This confidence interval is valid since the sampling distribution of sample mean would be approximately normal with sample size of 436. 95% of random samples have a sample mean between $80.31 and $89.11. We are 95% confident that the average spending of all American adults over this holiday season is between $80.31 and $89.11.
Mathematics
1 answer:
Tatiana [17]3 years ago
6 0

Answer:

<em>-A 90% confidence interval would be narrower than the 95% confidence interval if we don't need to be as sure about our estimate. </em>

<em>-This confidence interval is not valid since the distribution of spending in the sample data is right skewed.</em>

<em>-The margin of error is $4.4.</em>

<em>-This confidence interval is valid since the sampling distribution of sample mean would be approximately normal with sample size of 436.</em>

<em>-We are 95% confident that the average spending of all American adults over this holiday season is between $80.31 and $89.11.</em>

<em />

Step-by-step explanation:

<em>A 90% confidence interval would be narrower than the 95% confidence interval if we don't need to be as sure about our estimate. </em>

TRUE. The 90% confidence is less strict in its probability of having the mean within the interval, so it is narrower than the 95% CI. It relies more in the information given by the sample.

<em />

<em>In order to decrease the margin of error of a 95% confidence interval to a third of what is is now, we would need to use a sample 3 times larger. </em>

FALSE. The margin of error is z*σ/(n^0.5). So to reduce it by two thirds, the sample size n needs to be 3^2=9 times larger.

<em>This confidence interval is not valid since the distribution of spending in the sample data is right skewed.</em>

FALSE. There is no information about the skewness in the sample.

<em>The margin of error is $4.4.</em>

TRUE. The margin of error is (89.11-80.31)/2=$4.4.

<em>We are 95% confident that the average spending of these 435 American adults over this holiday season is between $80.31 and $89.11.</em>

FALSE. The CI is related to the populations mean. We are 95% confident that the average spending of the population is between $80.31 and $89.11.

<em>This confidence interval is valid since the sampling distribution of sample mean would be approximately normal with sample size of 436.</em>

TRUE. This happens accordingly to the Central Limit Theorem.

<em>95% of random samples have a sample mean between $80.31 and $89.11.</em>

FALSE. The confidence interval refers to the population mean.

<em>We are 95% confident that the average spending of all American adults over this holiday season is between $80.31 and $89.11.</em>

TRUE. This is the conclusion that is looked for when constructing a confidence interval.

You might be interested in
Can anybody help me please? i dont get it :(
sweet [91]

Answer:

ay bro dont ask me

the answer above me is already correct

good luck broski

im jus here for the points

ily<3

Step-by-step explanation:

7 0
2 years ago
Alexis goes to the flower shop and buys 6 tulips and 4 daffodils. The total cost is $46. Marci goes to the same flower shop and
puteri [66]
Your answer can be two answer it can 126.12 or it can possibly be 96.80
4 0
3 years ago
Brainiest to whoever right
sasho [114]
Is there more context to the question?
6 0
3 years ago
Read 2 more answers
The graph shows the functions f(x), p(x), and g(x):
Kruka [31]
Two functions have equal values where their graphs cross.

A) The solution to the pair of equations
.. y = p(x)
.. y = f(x)
will be where the graphs intersect, at (x, y) = (-3, -3).


B) We already know that (-3, -3) is one solution to y=f(x). The graph also appears to go through the point (0, 0).


C) p(x) = g(x) where their graphs cross, at x = -6. Both functions have the value 1 for that value of x.
8 0
3 years ago
What is 1,374 times 6
UNO [17]

Answer:

8244

Step-by-step explanation:

8 0
2 years ago
Read 2 more answers
Other questions:
  • Please help me ,,.......
    11·1 answer
  • What is 3/8 divided by 3/4 ​
    5·1 answer
  • How do you know which variable goes with axis when you graph
    7·1 answer
  • What's the area of a rectangle measuring 13 in. × 12 in.? A. 50 sq. in. B. 25 sq. in. C. 156 sq. in. D. 144 sq. in.
    15·2 answers
  • I am stuck and I hate maths so please help me
    8·1 answer
  • You work 40 hours a week at a factory and make $2.00 per piece you create. It takes you
    10·2 answers
  • Need help on this!!!!
    11·1 answer
  • What is the value of x?<br><br><br><br> Enter your answer in the box.<br><br> x =
    12·1 answer
  • Angle A and B are congruent angles.•The measure of angle
    11·1 answer
  • What are the solutions to the equation x+4x5 = 0?
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!