A second-stage smog alert has been called in a certain area of Los Angeles County in which there are 90 industrial firms. An inspector will visit 30 randomly selected firms to check for violations of...

Extracted text: A second-stage smog alert has been called in a certain area of Los Angeles County in which there are 90 industrial firms. An inspector will visit 30 randomly selected firms to check for violations of regulations. (a) If 36 of the firms are actually violating at least one regulation, what is th nmf of the number of firms visited by the inspector that are in violation of at least one regulation? O Пx; 30, 0.4) O nb(x; 30, 0.4) O h(x; 30, 36, 90) О Бх;B 30, 0.4) O nb(x; 30, 36, 90) О Бх; 30, 36, 90) (b) If there are 900 firms in the area, of which 360 are in violation, approximate the pmf of part (a) by a simpler pmf. О hix; 30, 360, 900) O nb(x; 30, 0.4) O b(x; 30, 0.4) O nb(x; 30, 360, 900) O h(x; 30, 0.4) О Бix; 30, 360, 900) (c) For X = the number that are in violation among the 30 visited out of 900 firms, compute E(X) and V(X) both for the exact pmf and the approximating pmf in part (b). (Round your answers to two decimal places.) Compute E(X) and V(X) for the exact pmf. E(X) V(X) Compute E(X) and V(X) for the approximating pmf. E(X) V(X)