Question

question 7.

The ages of all kindergarten children are normally distributed with mean 3 years and standard deviation 8 months.

If 49 kindergarten children are randomly selected, what is the probability that their mean age will be younger than 2 years 10 months old?

Use Table A-2 and write your answer as a decimal with 4 decimal places.

Selected Answer 0.9599 was WRONG

Answer 1

                               
P ( X < 34 )                                   
Standardizing the value                                   
                               
                               
Z = -1.75                                  
                               
P ( X < 34 ) = P ( Z < -1.75 )                                   
P ( X < 34 ) = 0.0401