14: no she got 69% 38/55 = 69%
A = 1
b = -5
c = -4
x1 = 5.70
x2 = -0.70
<span>Therefore, the negative real number is -0.70.</span>
Answer:
C. 2.19
Step-by-step explanation:
A) The empirical rule tells you the probability of being within 1 standard deviation of the mean is 68%.
b) The probability that the sample mean falls within 3 standard deviations* of the mean is 99.7%.
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* The standard deviation of the sample mean is 1/√9 = 1/3 of the standard deviation of an individual sample. Hence the same limits (90-110) now cover 3 standard deviations of the sample mean.