Answer :
Answer:
Between 82.2 and 90
Between 90 and 97.8
Step-by-step explanation:
The Empirical Rule states that, for a normally distributed random variable:
68% of the measures are within 1 standard deviation of the mean.
95% of the measures are within 2 standard deviation of the mean.
99.7% of the measures are within 3 standard deviations of the mean.
In this problem, we have that:
Mean = 90
Standard deviation = 7.8.
According to the Empirical Rule, 34% of test scores fall into what range?
68% of the measures are within 1 standard deviation of the mean.
The normal distribution is symmetric, which means that 68/2 = 34% fall between one standard deviation of the mean and the mean and 34% fall within the mean and one standard deviation above the mean.
90 - 7.8 = 82.2
90 + 7.8 = 97.8
34% between 82.2 and 90
34% between 90 and 97.8
So the correct options are:
Between 82.2 and 90
Between 90 and 97.8