Answer:
64.62
Step-by-step explanation:
From the given mean and margin of error, the 99% confidence interval for the mean amount of money spent on lunch per week for all students is:
[$19.5, $22.5].
<h3>How to calculate a confidence interval given the sample mean and the margin of error?</h3>
The confidence interval is given by the sample mean plus/minus the margin of error, hence:
- The lower bound is the sample mean subtracted by the margin of error.
- The upper bound is the sample mean added to the margin of error.
For this problem, we have that:
- The sample mean is of $21.
- The margin of error is of $1.50.
Hence the bounds are given as follows:
- Lower bound: 21 - 1.50 = $19.50.
- Upper bound: 21 + 1.50 = $22.50.
Hence the interval is [$19.50, $22.50].
More can be learned about confidence intervals at brainly.com/question/25890103
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Answer:
<u>1. The number is 71.3</u>
<u>2. The number is 127.1</u>
<u>3. The number is 230</u>
<u>4. The number is 34</u>
Step-by-step explanation:
Let's find out the numbers, x, for each case:
1. 5% of it is 5% of it is 23% of 15.5
5% = 0.05
23% of 15.5 = 0.23 * 15.5 = 3.565
Then, we have:
0.05x = 3.565
x = 3.565/0.05
x = 71.3
<u>The number is 71.3</u>
2. 4% of it is 31% of 16.4
4% = 0.04
31% of 16.4 = 0.31 * 16.4 = 5.084
Then, we have:
0.04x = 5.084
x = 5.084/0.04
x = 127.1
<u>The number is 127.1</u>
3. 4.5% of it is 23% of 45
4.5% = 0.045
23% of 45 = 0.23 * 45 = 10.35
Then, we have:
0.045x = 10.35
x = 10.35/0.045
x = 230
<u>The number is 230</u>
4. 5.5% of it is 17% of 11
5.5% = 0.055
17% of 11 = 0.17 * 11 = 1.87
Then, we have:
0.055x = 1.87
x = 1.87/0.055
x = 34
<u>The number is 34</u>
Answer:
x = 12
Step-by-step explanation:
Here, we want to find the value of x
To do this, we use one of the circle tangent relationships
we have this as:
8^2= 4(4 +x)
8^2 = 16 + 4x
64 = 16 + 4x
64-16 = 4x
4x = 48
x = 48/4
x = 12
