X is a normally distributed variable with mean= 67 and standard deviation = 9 %3D What value of X separates the upper 17.36% of scores from those below X?

Suppose that the distance of fly balls hit to the outfield (in baseball) is normally distributed with a mean of 260 feet and a standard deviation of 50 feet. We randomly sample 49 fly balls.   -Find the 70th percentile of the distribution of the average of 49 fly balls

True or False. The standard deviation of the mean is less than the sample standard deviation because it estimates the variation of averages, which are more precise than single observations.

What percent of cases fall more than 1.5 standard deviations away from the mean?

IQ scores are normally distributed with a mean of 100 and a variance of 225. What percentage of people score between 130 and 145?

In a set of 48 months of data for medical the mean is 15 days and standard deviation of 4.2 how many months fewer than 19.2 days per month reported medical leave ( one standard deviation above the mean?

Resting pulse rates for healthy adults are found to have approximately a Normal distribution with a mean of 69 beats per minute and a standard deviation of 8.5 beats per minute. Between what two values do the central 80% of all resting pulse rates lie?  what is lower value and  upper value ?

After the physical training required during World War II the distribution of a mile run times for male students at the University of Illinois was approximately normal with a mean of 7.11 minutes in a standard deviation of 0.74 minutes what proportion of these students can run a mile in 5 minutes or less   Using the same data what percent of students would take between 6 and 8 minutes to run a mile

Suppose the length of human pregnancies from conception to birth varies according to a distribution that is normal with mean of 266 days and standard deviation of “alpha”. 11.7% of pregnancies last 284 days or more, find the variance of the distribution .

The number of hours per day a college student spends on homework has a mean of 5 hours and a standard deviation of 1 hours. Yesterday she spent 2 hours on homework. How many standard deviations from the mean is that?     3.00 standard deviations below the mean     1.50 standard deviations above the mean     3.00 standard deviations above the mean     1.50 standard deviations below the mean