Nationwide, the average waiting time until a electric utility customer service representative answers a call is 360 seconds. The Gigantic Kilowatt Energy Company randomly sampled 50 calls and found that, on average, they were answered in 335 seconds with a population standard deviation of 55 seconds. Can the company claim that they are faster than the average utility at α = 0.05?

answer: 33 ( approx)

step-by-step explanation:

since, in the linear regression formula, the slope is the a in the equation y = b + ax ( by comparing it with the general equation of line y = mx + c )

where,

here given table is,

price ($), x   :           18         23       25       29       30       33

pairs sold, y :         16         13         10       8         6       2

so, ,   ,   ,

and   ,

thus, slop of the given line is,

⇒  

⇒   ≈ 33