The following table shows the probability distribution for a discrete random variable. x 12 15 17 20 22 24 25 30 p(x) 0.07 0.21 0.17 0.25 0.05 0.04 0.13 0.08 what is the mean of this discrete random variable? (that is, what is e(x), the expected value of x? ) a. 20 b. 19.59 c. 20.625 d. 21

The mean of this discrete random variable can be calculated by finding for the summation of the weighted average:

Mean = Summation (Xi * P(Xi))

Therefore,

Mean = 12 (0.07) + 15 (0.21) + 17 (0.17) + 20 (0.25) + 22 (0.05) + 24 (0.04) + 25 (0.13) + 30 (0.08)

Mean = 19.59

Therefore the answer is letter B. 19.59

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

answer is b 92.6 hope you got it my guy