You are researching memory cards for your phone, and you keep track of a random sample of prices for various size (gigabyte) SD cards.

The data is plotted for you below.  

GigabytesPrice ($)
0.54.42
0.54.06
16.48
24.58
24.83
46.38
87.7
87.05
89.16
1610.26
3214.23
6421.09
102030405060456789101112131415161718192021GigabytesPrice ($)

a) Use technology to find the equation of the best-fit line. Let x represent gigabytes, and let y represent price. Remember to start your equation with "y=".
 

b) In your equation, what is the slope?

Use the units to interpret the slope in context. (Remember slope is rise/run.)

Helpful phrase: “y per x”

c) What would the best-fit line predict for the price of a 16 GB memory card? dollars

d) Look at the data table.  What is the price of a 16 GB memory card in this data set? dollars

e) Calculate how far your prediction in part (b) was off. (This “error” is called a residual. It is calculated as the actual value (part d) minus the predicted value (part c).)

Residual: dollars