Answer:
The test statistic is 
Step-by-step explanation:
We are interested in determining whether or not the proportion of the student who experience anxiety during the exam is significantly more than 80%.
At the null hypothesis, we test if the proportion is 80%, that is:

At the alternate hypothesis, we test if the proportion is more than 80%, that is:

The test statistic is:

In which X is the sample mean,
is the value tested at the null hypothesis,
is the standard deviation and n is the size of the sample.
80% is tested at the null hypothesis:
This means that 
A random sample of 100 students was taken. Eighty-five of the student in the sample experienced anxiety during the exam.
This means that 
The test statistic is



The test statistic is 
Answer: 6:5
Step-by-step explanation:
1/4 = 5/20
2/5 = 8/20
8/20 + 5/20 = 13/20 has been spent
The height of the oblique triangular pyramid is 18 units if the base area of 21 square units and a volume of 126 cubic units.
<h3>What is volume?</h3>
It is defined as a three-dimensional space enclosed by an object or thing.
We know the volume of an oblique triangular pyramid is given by:

Where b is the area of the base and h is the height of the pyramid.
We have b = 21 square units and V = 126 cubic units.

h = 18 units
Thus, the height of the oblique triangular pyramid is 18 units if the base area of 21 square units and a volume of 126 cubic units.
Learn more about the volume here:
brainly.com/question/16788902
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Answer:
Given sides 12, 16 and 20 can be the sides of right triangle.
Step-by-step explanation:
Sides of right triangle always follow the Pythagoras theorem.
i.e 
For the given Lengths 7, 40 and 41
We need to check if


That means, 
hence 7,40 and 41 can not be the sides of right triangle.
Next,
Given sides 12,16 and 20.
Again follow the similar process used in the above problem.

Therefore given sides 12,16 and 20 can be the sides of right triangle.