The regression line equation is

, the value of the slope is shown as constant 16 and it's a positive constant, hence the correlation between the amount of gas used and degree of the days is a POSITIVE correlation.
The answer is C. 29.04
You use the Pythagorean theorem for the diagonal side because it’s a right triangle then you add all the sides and get C
Answer: Amount of 35% solution required = 100 milliliters
Amount of 87% solution required = 30 milliliters
Step-by-step explanation:
Given: Total solution required = 130 milliliters
Let x = Amount of 35% solution (in milliliters).
Then, Amount of 87% solution required = 130 - x
As per given,
Concentration = 0.35x +0.87(130-x)=0.47(130)

Hence, Amount of 35% solution required = 100 milliliters
Amount of 87% solution required = 130-100 milliliters =30 milliliters
3 hours is the correct answer