Answer:
0.02275
Step-by-step explanation:
We have been given that the time needed to complete a final examination in a particular college course is normally distributed with a mean of 80 minutes and a standard deviation of 10 minutes. We are asked to find the probability of completing the exam in one hour or less.
We know that 1 hour equals 60 minutes. First of all, we will find the z-score corresponding to 60 minutes.

z = z-score,
x = Sample score,
= Mean,
= Standard deviation.



Now, we will use normal distribution table to find area under z-score of
as:


Therefore, the probability of completing the exam in one hour or less is 0.02275.
The square root of .25 is rational because it is a terminating decimal.
√(.25)=05
Answer:
18
Step-by-step explanation:
The formula for this is a x b = c x d where a is SR, b is FR, c is QR and d is PR. This will give us the equation 9(16) = 8(5x + 8); 144 = 40x + 64; 80 = 40x; x = 2. Now, plug this into PR which will be 5(2)+8 = 18. This is your answer.
Answer:
A and B
Step-by-step explanation:
Parallel lines are lines which have the same slope. Perpendicular lines have negative reciprocal slopes.
For the options:
A. Both equations have 7/5 as the slope. They are parallel.
B. The slopes are 1 and -1. These are perpendicular.
C. The slopes are 9/2 and are parallel.
D. The slopes are 7/3 and -3/7. They are perpendicular.
The solution is A and B.