Answer:
B.
Step-by-step explanation:
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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Answer:
(c) micrograms (µg)
Step-by-step explanation:
Answer:
x = -9, y = 6.
Step-by-step explanation:
-x + y = 15
-5x - 3y = 27
From the first equation:
y = x + 15.
Substituting for y in second equation:
-5x - 3(x + 15) = 27
-8x - 45 = 27
-8x = 72
x = -9.
Now plug x = -9 into equation 1
-(-9) + y = 15
y = 15 -9 = 6.
Based on the information given, it should be noted that the mean and standard deviation of Y will be 0.4899 and 0.699 respectively.
<h3>Calculating the mean.</h3>
Based on the information given, it should be noted that the probability distribution for y will be:
Y 0 1. 2
Probability 0.63. 0.25. 0.12
The mean of Y will be:
= (0 × 0.63) + (1 × 0.25) + (2 × 0.12)
= 0 + 0.25 + 0.25
= 0.49
The variance will be 0.4899. Therefore, the standard deviation will be:
= ✓0.4899
= 0.699
Learn more about mean on:
brainly.com/question/19243813
