Answer:
The value that represents the 90th percentile of scores is 678.
Step-by-step explanation:
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean
and standard deviation
, the zscore 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 pvalue, we get the probability that the value of the measure is greater than X.
In this problem, we have that:

Find the value that represents the 90th percentile of scores.
This is the value of X when Z has a pvalue of 0.9. So X when Z = 1.28.




The value that represents the 90th percentile of scores is 678.
5/10 and 2/10 beacuse tenth is the bottom number
The diagram in the question is a cylinder.
;The volume of a cylinder is given by;
Volume = πr²h
;Where π=3.14
r⇒radius of the base of the cylinder and
h ⇒ height of the cylinder.
∴Volume = 3.14×5²×3
=235.5 ft³
To the nearest cubic = 236 ft³
Answer:

Step-by-step explanation:
Recall that
. Using this, we can simplify and combine the two terms:
. Therefore, the terms may be combined.
The square root -38 is sqrt(38)i, or approximately 6.2i.