SOLUTION: Suppose a test of coordination for first graders is scored so that the mean for all first graders is 50 and the standard deviation is 15. If we assume further that the distribution

Question 1009752: Suppose a test of coordination for first graders is scored so that the mean for all first graders is 50 and the standard deviation is 15. If we assume further that the distribution is normal, what percent of the first graders score: A. Between 40 and 70?. B. Below 30 ?. C. Above 75?
Answer by Boreal(15235) (Show Source): You can put this solution on YOUR website!
z=(x-mu)/sigma
the first is z between -2/3 and +4/3, which is 0.6563
The second is z < -4/3, and this is 0.0912
The third is z>(5/3) and this is 0.0478.
RELATED QUESTIONS
The reading test scores for the population is fifth graders is normally distributed with... (answered by ewatrrr)

The reading test scores for the population of fifth graders is normally distributed with (answered by Shin123)

The reading test scores for the population of fifth graders is normally distributed with... (answered by Theo,ikleyn)

a school bus contains 8 first graders and 10 second graders. if two children are are what (answered by stanbon)

The heights of a random sample of 6 fifth - graders have a sample mean of 54.68 inches... (answered by Edwin McCravy)

Assume that the mean SAT score in Mathematics for 11th graders across the nation is 500, (answered by stanbon)

Assume that the mean score on a certain aptitude test across the nation is 100, and that... (answered by stanbon)

Assume that the mean score on a certain aptitude test across the nation is 100, and that (answered by stanbon)

Assume that the mean score on a certain aptitude test across the nation is 100, and that... (answered by robertb)