Question

The equation y = 6.3x + 67.4 is the equation of a linear model in a scatter plot comparing the ages of boys between 2 and 10 years old (x) and their average heights in centimeters (y). What is the average height of a 5-year-old boy?

98.9 cm

78.7 cm

67.4 cm

62.4

Answer 1

The average height of a 5 year-old-boy ( x = 5 ) :
y = 6.3 x + 67.4
y = 6.3 * 5 + 67.4 = 31.5 + 67.4 = 98.9
Answer:
A ) 98.9 cm

Answer 2

y = 6.3x + 67.4
The average height of a 5 year old boy is
6.3(5) + 67.4 = 31.5 + 67.4 = 98.9 cm