A quarterback completes 18 of 33 passes during the first three quarters of a football game. He completes every pass in the fourth quarter and 62.5% of his passes for the entire game. How many passes does the quarterback throw in the fourth quarter?

He throws 7 passes

Step-by-step explanation:

say he throws x more completed passes.

62.5% = 5/8. So, counting up all the completions, we must have

18 + x = 5/8 (33+x)

He total completes:

18 passes during the first three quarters and x passes

during the fourth quarter = 18 + x passe

He total make:

33 throws during the first three quarters and x throws

during the first the fourth quarter = 33 + x

62.5 % = 62.5 / 100 = 0.625

Proportion is:

( 18 + x ) / ( 33 + x ) = 0.625

Multiply both sides by 33 + x

18 + x = ( 33 + x ) ∙ 0.625

18 + x = 33 ∙ 0.625 + x ∙ 0.625

18 + x = 20.625 + 0.625 x

Subtract 18 to both sides

18 + x - 18 = 20.625 + 0.625 x - 18

x = 2.625 + 0.625 x

Subtract 0.625 x to both sides

x - 0.625 x = 2.625 + 0.625 x - 0.625

0.375 x = 2.625

Divide both sides by 0.375

x = 2.625 / 0.375 = 7

In the fourth quarter throw 7 passes.

Proof:

( 18 + 7 ) / ( 33 + 7 ) = 25 / 40 = 0.625 = 62.5 %

line or a linear equation graph

step-by-step explanation: