-A consumer organization inspecting new cars found that many hadappearance defects​ (dents, scratches, paint​ chips, etc.). Whilenone had more than three of these​defects,
6​% had​ three, 12% had​ two, and 26% had one defect. Find theexpected number of appearance defects in a new car and the standarddeviation. Compute the expected value of the number of appearancedefects.
​E(appearance
​defects)equals=. 68.68
​(Round to two decimal places as​ needed.)
Compute the standard deviation of the number of appearancedefects.
​SD(appearance
​defects)equals= _____________________
​(Round to two decimal places as​ needed.)
-A salesman normally makes a sale​ (closes) on 70% of hispresentations. Assuming the presentations are​ independent, findthe probability of each of the following.​
a) He fails to close for the first time on his sixthattempt.​
b) He closes his first presentation on his fifth attempt.
​c) The first presentation he closes will be on his secondattempt.
​d) The first presentation he closes will be on one of his firstthree attempts.
A manufacturer of game controllers is concerned that itscontroller may be difficult for​ left-handed users. They set out tofind lefties to test. About 11% of the population is​ left-handed.If they select a sample of 99 customers at random in their​ stores,what is the probability of each of the outcomes described in partsa through f​ below?
​a) The first lefty is the third person chosen.The probabilityis _____________________
​(Round to four decimal places as​ needed.)
​b) There are some lefties among the 99 people.The probabilityis _______________________
​(Round to four decimal places as​ needed.)
​c) The first lefty is the second or third person. Theprobability is __________________________
​(Round to four decimal places as​ needed.)
​d) There are exactly 3 lefties in the group. The probability is__________________________
​(Round to four decimal places as​ needed.)
​e) There are at least 3 lefties in the group. The probabilityis __________________________
​(Round to four decimal places as​ needed.)
​f) There are no more than 3 lefties in the group. Theprobability is _________________________
​(Round to four decimal places as​ needed.)
