We are given equation: c=6.4w, where the cost c for w pounds of walnuts.
w represents the number of pounds of walnuts.
Number of pounds could be in decimals.
The value of w = 2.5 represents 2.5 pounds of walnuts.
On plugging w=2.5 in c=6.4w equation, we get.
c=6.4×2.5 = $16.
Therefore, for 2.5 pounds of walnuts the total cost is $16.
Hence, <u>a value of 2.5 for w make sense in this situation. It shows that cost of 2.5 pounds of walnuts is $16, where cost of each pound of walnuts is 6.4.</u>