Disk drives have been getting larger. Their capacity is now often given in terab
ID: 3217147 • Letter: D
Question
Disk drives have been getting larger. Their capacity is now often given in terabytes (TB) where 1 TB = 1000 gigabytes, or about a trillion bytes. A survey of prices for external disk drives found the data shown to the right. For this data, we want to predict Price from Capacity. Complete parts a through h. a) Find the slope estimate, b_1. b_1 = 95.98 (Round to two decimal places as needed.) b) What does it mean, in this context? A. It indicates the additional capacity in gigabytes for each additional dollar of price. B. It indicates the additional capacity in TB for each additional dollar of price. C. It indicates the price for a hard drive with no capacity. This could be interpreted as the cost of the parts common to all drives. D. It is meaningless and should not be interpreted. E. It indicates the additional price in dollars for each additional TB of capacity. c) Find the intercept, b_0. b_0 = ____ (Round to two decimal places as needed.)Explanation / Answer
Line of Regression Y on X i.e Y = bo + b1 X
Mean of X = X / n = 1.4
Mean of Y = Y / n = 159.6771
(Xi - Mean)^2 = 15.4942
(Yi - Mean)^2 = 144740.72
(Xi-Mean)*(Yi-Mean) = 1487.1939
b1 = (Xi-Mean)*(Yi-Mean) / (Xi - Mean)^2
b1 = 1487.1939 / 15.4942 = 95.9839
bo = Y / n - b1 * X / n
bo = 159.6771 - 95.9839*1.4 = 25.2996
Y = bo + b1 X
Y'=25.2996+95.9839*X