Answer:

General Formulas and Concepts:
<u>Pre-Algebra I</u>
- Order of Operations: BPEMDAS
<u>Algebra I</u>
- Midpoint Formula:

Step-by-step explanation:
<u>Step 1: Define</u>
R (9, 3)
S (-1, -9)
<u>Step 2: Find midpoint</u>
- Substitute:

- Subtract:

- Divide:

I hope this picture helps. I'll elaborate if needed!
Answer:
Keenan's z-score was of 0.61.
Rachel's z-score was of 0.81.
Step-by-step explanation:
Z-score:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean
and standard deviation
, the z-score of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
Keenan scored 80 points on an exam that had a mean score of 77 points and a standard deviation of 4.9 points.
This means that 
So



Keenan's z-score was of 0.61.
Rachel scored 78 points on an exam that had a mean score of 75 points and a standard deviation of 3.7 points.
This means that
. So



Rachel's z-score was of 0.81.
Volume=[(4πr^3)/3]/2=[(4π(70)^3)/3]/2 is approximately 718378 ft^3