When Sarah was 10 years old, she was 130 cm tall.Two years later, her height had increased by 15%.Find Sarah's height when she was 12 years old.

The average height of 10 boys is 170 cm. If one boy’s height is neglected, the average height is increased by 1 cm. Find the height of the neglected boy?

The average height of the students of a class would be increased by 6 cm if 12 children were 8 cm taller. How many children are there in the class?

There are some girls and boys in a group. The average height of the girls is 135cm and the average height of the boys is 150cm. Given that the the average height of all the children in the group is 138cm, what fraction of the children are girls?

Eighteen years ago, the ratio of A’s age to B’s age was 8 : 13. Their present ratios are 5 : 7. What is the present age of A

A pediatrician records the age x (in yr) and average height y (in inches) for girls between the ages of 2 and 10.a. Use the points (2, 37) and (6, 50) to write a linear model for these data.b. Use the model to forecast the average height of 11-yr-old girls.Select one:a. a. y = 3.25x + 30.5; b. 66.25 in.b. a. y = 3.25x + 30.5; b. 67.25 in.c. a. y = 3x + 29.5; b. 63.25 in.d. a. y = 3x + 29.5; b. 62.5 in.