Using the normal distribution, it is found that 58.97% of students would be expected to score between 400 and 590.
<h3>Normal Probability Distribution</h3>
The z-score of a measure X of a normally distributed variable with mean
and standard deviation
is given by:

- The z-score measures how many standard deviations the measure is above or below the mean.
- Looking at the z-score table, the p-value associated with this z-score is found, which is the percentile of X.
The mean and the standard deviation are given, respectively, by:

The proportion of students between 400 and 590 is the <u>p-value of Z when X = 590 subtracted by the p-value of Z when X = 400</u>, hence:
X = 590:


Z = 0.76
Z = 0.76 has a p-value of 0.7764.
X = 400:


Z = -0.89
Z = -0.89 has a p-value of 0.1867.
0.7764 - 0.1867 = 0.5897 = 58.97%.
58.97% of students would be expected to score between 400 and 590.
More can be learned about the normal distribution at brainly.com/question/27643290
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Answer:
The answer is <u><em>7</em></u>!
Step-by-step explanation:
(x-4) (x) = 21, x^2 - 4x = 21, x^2 - 4x - 21 = 0, (x - 7) (x + 3) = 0, x = 7 and -3; x can't be negative so the answer is 7!
x = 7 and x - 4 (other side) = 3
5x - 5 = x + 11
5x = x + 16
4x = 16
x = 4
7/2=y/3
21=2y
Y=21/2
Hope this helps!