If the standard deviation of an exam is 5, the z-score us 1.95 and the mean is 80, the actual test score is; 89.75
<h3>How to solve z-score problems?</h3>
We are given;
Standard deviation; s = 5
z-score = 1.95
Mean = 80
Formula for z-score is;
z = (x' - μ)/σ
Thus;
1.95 = (x' - 80)/5
1.95 * 5 = (x' - 80)
9.75 = x' - 80
x' = 80 + 9.75
x' = 89.75
Read more about Z-score Problems at; brainly.com/question/25638875
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Use the geometric mean for right triangles here. Like this

. Cross multiply to get

, and

. That simplifies down to

. Pull out the 9 as a perfect square of 3 and you're left with

, first choice above.
3x - 9y - 5x - 7y
Combine like terms
( 3x + - 5x ) + ( - 9y + - 7y )
= - 2x - 16y
Step-by-step explanation:
Bc is also 20 answer is 400