studying the sleep habits of teens, steve looks at 120 sample means. the data is normally distributed. how…

studying the sleep habits of teens, steve looks at 120 sample means. the data is normally distributed. how many means should he expect to see two standard deviations above the mean of all of the sample means?\na. 95\nb. 6\nc. 5\nd. 3

studying the sleep habits of teens, steve looks at 120 sample means. the data is normally distributed. how many means should he expect to see two standard deviations above the mean of all of the sample means?\na. 95\nb. 6\nc. 5\nd. 3

Answer

Explanation:

Step1: Recall normal - distribution property

In a normal distribution, approximately 95% of the data lies within 2 standard deviations of the mean. So the percentage of data above 2 standard deviations from the mean is $\frac{100 - 95}{2}=2.5%$.

Step2: Calculate the number of sample means

We have 120 sample means. Multiply the total number of sample means by the percentage of data above 2 standard deviations. So the number of means is $120\times0.025 = 3$.

Answer:

D. 3