Could someone please help me with part b ?

The answer is c, C=1.5w + 5

Step-by-step explanation:

Let's write a general equation first,

C = mw + b, where C represents the shipping cost, w is the weight, m and b are non-zero constants.

By using the set of data in the table, what we can do is to substitute the corresponding values into our general equation. [Use any 2 set of numbers]

11 = 4w + b --(1)

17 = 8w + b --(2)

Here we got 2 equations, 2 unknown, thus we can get

w = 3/2, b = 5

The answer is c, C=1.5w + 5

[Noted that if you already got the slope(the yellow words), you can simply substitute one set of numbers into C=1.5w + b to find the value of b]