Please answer Will mark brainiest

a = 8cm

Step-by-step explanation:

13 + 8 + 7 + 9 + 3 = 40

40 divided by 5 = 8

the 5 comes from how many numbers they're are

mean = adding up the numbers and dividing it by how many numbers they're are

pls mark as branliest

btw = I'm sorry if I didn't answer the 2nd question

[(7*120)+(8*124)+(13*128)+(9*132)+(3*136)]/40 = 127 3/10 cm ≅ 130

another way (120+140)/2=260/2=130

because The estimate is the average of the smallest possible value and the largest possible  and not the real number.(you can right different explanation)

use an equation of ratios to determine the amount of gas needed to fill the tank.

    0.2             0.8

  =    

288.75             x

                                                              231 gal

so, 0.2x = (0.8)(288.75 gal), and x = = 1155 gal.

                                                                0.2

it would take 1155 gal. to fill the tank.

the cost would be

1155 gal         $3

* = $3465   (answer)

      1           1 gal

hope this you