SOLUTION: 2. In 2000, as reported by ACT Research Service, the mean ACT Math score was μ=20.7. If ACT Math scores are normally distributed with σ = 5, answer the following question

Algebra.Com
Question 328042: 2. In 2000, as reported by ACT Research Service, the mean ACT Math score was μ=20.7. If ACT Math scores are normally distributed with σ = 5, answer the following questions.
a) What is the probability that a randomly selected student has an ACT Math score less than18?

b) What is the probability that a random sample of 10 ACT test takers had a mean ACT Math score less than 18?

Answer by stanbon(75887)   (Show Source): You can put this solution on YOUR website!
In 2000, as reported by ACT Research Service, the mean ACT Math score was μ=20.7. If ACT Math scores are normally distributed with σ = 5, answer the following questions.
a) What is the probability that a randomly selected student has an ACT Math score less than 18?
---
z(18) = (18-20.7)/5 = -0.54
P(x < 18) = P(z < -0.54) = 0.2946
============================================
b) What is the probability that a random sample of 10 ACT test takers had a mean ACT Math score less than 18?
---
z(18) = (18-20.7)/[5/sqrt(10)] = -1.7076 = 0.0439
=============
Cheers,
Stan H.

RELATED QUESTIONS

11. In 2000, as reported by the ACT Research Service, the mean ACT Math score was 20.7.... (answered by Boreal)
Trevor wants to buy a local restaurant. 60% of the business days it's open, the... (answered by stanbon)
The ACT exam math section scores are normally distributed with mean 18 and standard... (answered by stanbon)
A study was conducted on students from a particular high school over the last 8 years.... (answered by ewatrrr)
A study was conducted on students from a particular high school over the last 8 years.... (answered by Theo)
There are two major tests of readiness for college, the ACT and the SAT. ACT scores are... (answered by Theo)
There are two major tests of readiness for college, the ACT and the SAT. ACT scores are... (answered by Boreal)
Amanda took the SAT and scored 680 on the mathematics part. The distribution of SAT math... (answered by jim_thompson5910)
HELP!!!!! The mean ACT math score in 2001 was 20.7, with an approximate standard... (answered by nabla)