Answer:
49º
Step-by-step explanation:
Answer:
x=11
Step-by-step explanation:
(7x+14)=(9x-8)
7x-9x=-14-8
-2x=-22
-2x/-2=-22/-2
x=11
We have been given that the ages of students in a school are normally distributed with a mean of 15 years and a standard deviation of 2 years.
We are asked to find the percentage of students that are between 14 and 18 years old.
First of all, we will find z-score corresponding to 14 and 18 using z-score formula.




Similarly, we will find the z-score corresponding to 18.



Now we will find the probability of getting a z-score between
and
that is
.

Using normal distribution table, we will get:


Let us convert
into percentage.

Therefore, approximately
of the students are between 14 and 18 years old.