Answer:
mmm
Step-by-step explanation:
Consider the right triangle ABC with legs AB=4, AC=3 and hypotenuse BC=5. Angle B has

and

.
Since O lies in second quadrant

and

.
Answer:
.
The value of
is 31
Explanation:
The given expression is 
We need to determine the value of 
The value of
can be determined by substituting
in the expression 
Thus, we have,

Adding the terms, we have,

Thus, the value is 31.
Therefore, the simplified value of the expression by substituting
in the expression
is 31.
Answer:
The 98% confidence interval for the mean number of hours of study time per week for all students is (20.9, 25.1).
Step-by-step explanation:
Confidence interval:
Sample mean plus/minus the margin of error.
In this question:
Mean of 23.
Margin of error 2.1.
Then
23 - 2.1 = 20.9
23 + 2.1 = 25.1
The 98% confidence interval for the mean number of hours of study time per week for all students is (20.9, 25.1).
4+1/ 20
It would be in a fraction like form.