4+x=18, the sum would make it an addition problem and x would represent "a number".
Using the t-distribution, it is found that the test statistic for the hypotheses test is given by:

<h3>What are the hypotheses tested?</h3>
At the null hypotheses, it i tested if the mean difference remains the same, that is:

At the alternative hypotheses, it is tested if it has decreased, hence:
.
<h3>What is the test statistic?</h3>
The test statistic is given by:

The parameters are:
is the sample mean.
is the value tested at the null hypothesis.
- s is the standard deviation of the sample.
The parameters are given as follows:
.
Hence the test statistic is given by:


More can be learned about the t-distribution at brainly.com/question/16162795
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Answer:
D. 4.5%.
Step-by-step explanation:
Interest earned in 6 months = 572.6 - 560 = $12.60.
As a percentage this is (12.60 * 100) / 560
= $ 2.25%.
So the annual interest is 2 * 2.25
= 4.5%.
The answer is 4 isn’t it?
Deandre = x
Kala = x + 6
Eric = 3(x+6)
x + x + 6 + 3(x+6) = 119
2x + 6 + 3x + 18 = 119
5x + 24 = 119
5x = 95, x = 19
Deandre has $19
Kala has 19 + 6 = $25
Eric has 3(25) = $75