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
12345 [234]
3 years ago
7

In a survey, 24 people were asked how much they spent on their child's last birthday gift. The results were roughly bell-shaped

with a mean of $42 and standard deviation of $2. Construct a confidence interval at a 98% confidence level.
Mathematics
1 answer:
erica [24]3 years ago
7 0

Answer:

The 98% confidence interval for the mean amount spent on their child's last birthday gift is between $40.98 and $43.02.

Step-by-step explanation:

We have the standard deviation for the sample, which means that the t-distribution is used to solve this question.

The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So

df = 24 - 1 = 23

98% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 23 degrees of freedom(y-axis) and a confidence level of 1 - \frac{1 - 0.98}{2} = 0.99. So we have T = 2.5

The margin of error is:

M = T\frac{s}{\sqrt{n}} = 2.5\frac{2}{\sqrt{24}} = 1.02

In which s is the standard deviation of the sample and n is the size of the sample.

The lower end of the interval is the sample mean subtracted by M. So it is 42 - 1.02 = $40.98.

The upper end of the interval is the sample mean added to M. So it is 42 + 1.02 = $43.02.

The 98% confidence interval for the mean amount spent on their child's last birthday gift is between $40.98 and $43.02.

You might be interested in
Robin and Meg are traveling from New York to Florida, and plan to stop at three different campgrounds along the way. After choos
matrenka [14]

You are correct. For each of the three possibilities for their second day, there are two possibilities for the third day.

The total number of possibilities is 3*2 = 6.

6 0
3 years ago
2x × 9 = ?<br><br> What is the answer?<br> Is the answer 18x?
scoundrel [369]

Answer:

The answer is 18x.

Step-by-step explanation:

2x times 9 is 18x because when you multiply 9 times 2, you get 18 and the x carries over.


5 0
3 years ago
Read 2 more answers
You must write your answer in fully simplified form.<br>2t= -12​
Katarina [22]

Answer:

t=-6

Step-by-step explanation:

4 0
2 years ago
Write an equation of the line that passes through 3,1 and 0,10
elena-14-01-66 [18.8K]

Answer:y = -3x + 10

Step-by-step explanation:

To find an equation of a line that passes through two points, we have to first find the slope between the two equation. We can do this by using the slope formula:

where (x₁, y₁) and (x₂, y₂) are the two points that we are finding the slope between.

Lets make (x₁, y₁) equal to (0, 10) and (x₂, y₂) equal to (3, 1). Now we plug them into the slope formula:

So the slope between the two points is -3.

From here, I would normally take one of the points given to us and plug in the point and slope into the point-slope form of a line and then simplify until we get it in slope-intercept form. But if you look carefully, the y-intercept is given to us as the point (0, 10). So we now know that the y-intercept of the line is 10. We can now take the y-intercept and the slope and plug it into the slope-intercept form of a line to get out equation:

y = mx + b

plug in -3 for m (the slope) and 10 for b (the y-intercept)

y = -3x + 10

So now we have our equation.

I hope you find my answer and explanation helpful. Happy studying. :)

3 0
3 years ago
Graph this function:<br> y= 5x - 18
lutik1710 [3]
The graph is shown below. 

5 0
3 years ago
Other questions:
  • Find the lowest common denominator of 3/x^3y and 7/xy^4
    14·2 answers
  • Please don't put absurd answers, ty.
    5·2 answers
  • A slope of -3 passing through the points (6,-14)
    12·1 answer
  • What is the coordinate for the image of point H(2, –6) under a 90° clockwise rotation about the origin? H’(–6, –2) H’(6, –2) H’(
    7·2 answers
  • T=p(0.09)2/3, where p is the original amount in the account, if the original account amount was $2570, what is her current balan
    12·1 answer
  • Which item has the lowest unit price
    11·1 answer
  • Helppp I will make u a brainlist!!
    15·2 answers
  • 20 10<br>40<br>30.<br>15<br>40<br>70<br>25<br>20<br>30<br>100<br>40<br>50​
    14·1 answer
  • Suppose f(x) = 2x + 3. Find f(-.5).
    11·1 answer
  • 2х - 7y = 14<br> Find the x and y- intercepts then graph them.
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!