The ages of students in a school are normally distributed with a mean of 15 years and a standard deviation of 2 years. Approximately what percent of the students are between 14 and 18 years old?

Question

anonymous · Answer

24.17% 

 62.47% 

 30.85% 

 93.32%

lopus · Answer

$$P(14<x \le18)=P(\frac{ 14-15 }{ 2 }<z \le \frac{ 18-15 }{ 2 })$$

anonymous · Answer

How do I find the percent of the students from here?

lopus · Answer

$$P(-0.5<z \le1.5)=P(z \le 1.5)-[1-P(z \le 0.5)]$$

lopus · Answer

tell me what number you find in the table for 1.5

anonymous · Answer

0.4332?
OK, what do I do now w. this number?

lopus · Answer

sorry man in this table: http://4.bp.blogspot.com/_5u1UHojRiJk/TEh9BHxxPUI/AAAAAAAAAIQ/DafeQNMYFoE/s1600/ztable.gif

anonymous · Answer

@lopus ?

lopus · Answer

this number is z<1.5   later do     z<0.5  and replace it in equation

lopus · Answer

tell me you can solve it