Picture problem using proportion (ACT)

A photographic negative measures 1  7/8 inches  by  2  1/2 inches.  If the longer side of the printed picture is to be 4 inches, what will be the length of the shorter side of the printed picture?
A.)  3  1/8 inches
B.)  3 inches
C.)  2  3/4 inches
D.)  2  1/2 inches
E.)  2  3/8 inches

Currently it is 1  7/8  by  2  1/2
The longer side is to be 4 inches

y inches by 4 inches will be the new dimensions of the printed picture

Set up a proportion

1  7/8         2  1/2
--------  =   ---------- {set up the proportion}
   y                4

15/8           5/2  
--------  =  -------- {changed all fractions to improper fractions}
   y               4

4(15/8) = (5/2)y {cross-multiplied}
15/2 = (5/2)y {cancelled and multiplied what's left}
y = 3 {divided both sides by 5/2, multiplying by reciprocal, 2/5}

The length of the shorter side of the printed picture will be 3.

B.)  3

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