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:
A : ±2
Step-by-step explanation:
Add 14 and you have ...
... x² = 4
Take the square root and you have ...
... x = ±√4 = ±2
Answer:
<h3>The answer is 74 cm</h3>
Step-by-step explanation:
The area of a rectangle = length × width
Since we are finding the width
We have

From the question
area = 6216 cm²
length = 84 cm
The width is

We have the final answer as
<h3>74 cm</h3>
Hope this helps you
Answer:
x²-8x-1=0
comparing above equation with ax²+bx+c=0
a=1
b=-8
c=-1
x=

=(--8+-√(64-4×1×-1)/2×1
=8+-√(64+4)/2
taking positive
x=(8+√68)/2=2(4+√17)/2=4+√17
taking negative
x=(8-√68)/2=2(4-√17)/2=4-√17