Answer: B) 18
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Explanation:
x = number of packs of yogurt (column 1)
y = number of ounces of yogurt (column 2)
To get the constant of proportionality k, we divide y over x
k = y/x
k = 36/2 = 18 .... from row 1
k = 54/3 = 18 ... from row 2
k = 90/5 = 18 .... from row 3
This k = 18 value means that each time x goes up by 1, the value of y goes up by 18. This is the slope of the line y = 18x, so it represents the rate of change.
Put another way: 1 pack of yogurt is 18 ounces
