Hi,

 mean = 120  and sd = 10

Using TI Calculator

a) Find the probability that a randomly selected sample will take more than 150 minutes to complete the test.

 normalcdf(150, 9999, 100, 10).   

|Note: The 9999 is used as the larger value to be at least 5 standard deviations from the mean.

 b)Find the probability that the mean time taken to complete the test by a random sample of 16 would be between 122 and 126. 

normalcdf(122, 126, 100,10). 

RELATED QUESTIONS

Please help me solve this problem:
In a driving school, the time taken by student... (answered by stanbon)

The time needed to complete the final examination of MGSC 301 is normally distributed... (answered by stanbon)

The time required to complete a final examination in a particular college course is... (answered by ewatrrr)

The time needed to complete a final examination in a particular college course is... (answered by Boreal)

The time taken for a student to complete an exam is normally distributed with a mean of... (answered by Boreal)

The time taken for a student to complete an exam is normally distributed with a mean of... (answered by ikleyn)

Let x denote the time taken to run a road race. Suppose x is approximately normally... (answered by ewatrrr)

What propotion of A students studying statistics ?
The amount of time devoted to... (answered by rothauserc)

Let x denote the time taken to run a road race. Suppose x is approximately normally... (answered by CPhill)