Question

Done AA Ć myopenmath.com 3 vetans 47 p Score on last try: 4 of 7 pts. See Details for more. > Next question You can retry this question below The manager of a computer retails store is concerned that his suppliers have been giving him laptop computers with lower than average quality. His research shows that replacement times for the model laptop of concern are normally distributed with a mean of 4.5 years and a standard deviation of 0.5 years. He then randomly selects records on 17 laptops sold in the past. Round the answers of following questions to 4 decimal places. a. What is the distribution of X? X-N( 4.5 0.5 b. What is the distribution of ? -N4.5 c. What is the probability that one randomly selected laptop is replaced less than 4.6 years? d. For 17 laptops, find the probability that the average replacement time is less than 4.6 year. e. For part d), is the assumption of normal necessary? Yes No

Answer 1

Solution - Given no17 el= 4.5 years . = 0.5 years. of x ? what is Xu tus the distribution N (cel, o N ( 4.5, 0.5) 7? what is the distribution of k is NC 1,62) în N c 4.5, 0.25). O P [X<46 years ] PIXC 4.6 ] = prx- < 4.6 #45) = P ( 2 < 0.2) ? 1-PC270.22 1- 0:42074 ( from statisticed = 0.57926 = 0.5793 0'S 193. ( المهم PC XC 406 ) - a for 17 laptops find P ( 7 <4-6 years] [7C4.0 a pr kry < 46-45 bih osli - P ( 2 < 0.8246 2 = 1- P (270.822 = '- 0.2061) --- from statischeel = 0.79389 table) = 0.7935 | P (84 41 : 6: 19 3 1 @rostor port @ the assumption of name is necessary.