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
#SPJ1
Answer:
Step-by-step explanation:
96
Answer:5 days
Step-by-step explanation:
16 divided by 4=4 postcards a day
20 divided by 4=5
5 days in total
hope this helps . Please mark brainliest
Answer:
x = 25.35 (or 2129/84) and y = 4334.04 (or 121353/28)
Step-by-step explanation:
The given equations are set up and ready to go with substitution. Simply just plug in the first equation to the second equation as both are equal to y.
Step 1: Replace y in <em>y = 87x + 2129 </em>with <em>171x</em>
171x = 87x + 2129
Step 2: Subtract 87 x on both sides
84x = 2129
Step 3: Divide both sides by 84 to get x
x = 2129/84 or 25.35 (rounded)
To get y, simply plug in x into one of the 2 original equations. In this case, I will use the first equation:
y = 171 (25.35)
y = 121353/28 or 4334.04 (rounded)
You can check your work by plugging both solutions into the calculator and see if they equal each other. The values for these answers are solely based on the equations, so if you write the <em>equations </em>wrong themselves, then that means you have the values wrong as well.
Answer: f(n) = {f(1)=-4
{f(n) = f(n-1) / 20 if n > 1
Or Answer B.
Step-by-step explanation: