To find out which fish Sasha purchased, let's first calculate the cost of each fish per pound and see which one aligns with Sasha's purchase of 3/4 lb of fish for $5.40.
Here are the prices per pound for each type of fish:
- Salmon: $9.60/lb
- Tuna: $7.20/lb
- Swordfish: $8.40/lb
- Whitefish: $6.90/lb
Now, we can calculate the cost for 3/4 lb of each fish:
-
Salmon:
\[(\frac{3}{4}) \times 9.60 = 7.20\] -
Tuna:
\[(\frac{3}{4}) \times 7.20 = 5.40\] -
Swordfish:
\[(\frac{3}{4}) \times 8.40 = 6.30\] -
Whitefish:
\[(\frac{3}{4}) \times 6.90 = 5.175\]
Sasha bought 3/4 lb of fish for $5.40, which matches the cost of the Tuna at $5.40.
Thus, the fish Sasha chose was Tuna.