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.
Answer:
y=6
Step-by-step explanation:
y=kx
3=9k
k=3/9
k=1/3
y=kx
y=1/3 × 18
y=6
Answer:
55 Rs.
Step-by-step explanation:
cost of the milk:
15.5 x 30 = 465 Rs.
Gross sales of the milk:
26 x 20 = 520 Rs.
Profit:
520 - 465 = 55 Rs.
The answer is -30. The absolute value of -3 is 3. Then you evaluate the power of 6 to the power which is 36. Next you multiply the numbers 2 x 3 which is 6. Then calculate the two numbers left over 6 - 36 which is -30.