Answer:
3.98
Explanation:
From the above question,
Cost is directly proportional to the Number of pounds
Hence:
C ∝ N
= C = kN
Where k = Proportionality constant
We are told:
Last week, she bought two pounds and paid $7.96,
Hence:
7.96 = 2k
k = 7.96/2
k = 3.98
This week she bought only one half pound and paid $1.99,
1.99 = k × 1/2
k = 1.99/ 1/2
k = 3.98
Hence, the constant rate of proportionality is 3.98