Answer:
A score of 150.25 is necessary to reach the 75th percentile.
Step-by-step explanation:
Problems of normal distributions can be 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.
A set of test scores is normally distributed with a mean of 130 and a standard deviation of 30.
This means that 
What score is necessary to reach the 75th percentile?
This is X when Z has a pvalue of 0.75, so X when Z = 0.675.




A score of 150.25 is necessary to reach the 75th percentile.
Answer:
Should be 4.0(Not sure tho. my thought process is complicated but to me it makes sense)
Step-by-step explanation:
If y=10 and x =2.5, if y were to = 20, then x would equal 5. so you take that ratio, and say 6 is 3/5's the way to 10, so you also divide 2.5 by 3/5
you get 1.5, you add that to x already and you get 4.0
so if y=16, x should =4.0
Use x as the base variable. All others as x+(extra amount).
Answer:
The answer is B
Step-by-step explanation:
3
To calculate a fraction of a quantity, multiply the quantity by the numerator of the fraction and divide by the denominator
of 20 = (3 × 20 )/4 =
= 15
of 20 = (3 × 20 )/5 =
= 12