PLEASE HELP
The average daily temperatures of a city in the United States were recorded for one year. The graph below shows the information. What is the median and the standard deviation of the average daily temperatures of this city?
a. 90; 36
b. 36; 6
c. 84; 6
d. 84; 8

So the first thing we do is to multiply the top equation by 3. the reason i want to do this is i notice there will be a 6y on both equations and can possibly add/subtract them. so we get 6y = -3x + 27. adding that and the second equation we get 6x = 27-15 which is 12. divide by 6 and we get 2. ∴ x = 2. substituting 2 into the first equation we get 2y = -2 + 9 which is 7. divide by 2 and we get 7/2. ∴ y = 7/2, x = 2.

Wouldn’t it be six if all intervals are the same?