Fifteen percent of new residential central air conditioning units installed by a supplier
need additional adjustments requiring a service call. Assume that a recent sample of seven such units
constitutes a Bernoulli process. Interest centers on X, the number of units among these seven that need
additional adjustments.
(92) The probability that exactly 2 units need additional adjustments is about:
(A) 0.15 (B) 1.05 (C) 0.21 (D) 0.16
(93) The probability that at least 2 units need additional adjustments is about:
(A) 0.15 (B) 0.926 (C) 1.05 (D) 0.16
(94) The mean number of units that need additional adjustments is:
(A) 0.15 (B) 0.32 (C) 1.05 (D) 0.16
(95) The variance of X is:
(A) 0.8925 (B) 0.6654 (C) 0.0214 (D) 0.3225