【正文】 o n pnpq E r r o r S t dE r r o r S t dZ p l i m i t c o n f i d e n c e L o w e rE r r o r S t dZ p l i m i t c o n f i d e n c e Up p e r????????Abcot Confidence interval for continuous data A large disk drive manufacturer needs an estimate of the mean life it can expect from the magic media by reciprocally switching its digital state at 1MHz frequency. The development team has determined previously that the variance of the population life is 36 months, 和 had conducted a reliability testing for 100 samples, collecting data of its useful life as below: From the above data, what is the 95% confidence interval for the useful mean life of the magic media in a disk drive ? What does this mean ? Abcot Confidence interval for continuous data (con?t) Applying the confidence intervals equation: Upper confidence limit = + () = Lower confidence limit = – () = From the sample data given, Sample size, n = 100 Mean = (Sum of useful life) / 100 = 2775 / 100 = months Variance, ?2 = 36 months 標(biāo)準(zhǔn)偏差 , ? = 6 months Standard error, ?x = 6 / 10 = As such, there is 95% confidence level that the average useful life of the magic media to fall between 和 months. Abcot Confidence interval for discrete data Break into 4 or 5 teams, bined all the Mamp。 0 . 6 7 4 1 . 2 8 2 1 . 6 4 5 1 . 9 6 2 . 3 2 6 2 . 5 7 6 3 . 2 9 1A r e a u n d e r t h e c u r v ed f , ut ( a, u ) a Area under the curve Abcot Percentiles of the Normal Distribution / Z Distribution 0 0 . 0 1 0 . 0 2 0 . 0 3 0 . 0 4 0 . 0 5 0 . 0 6 0 . 0 7 0 . 0 8 0 . 0 90 0 . 5 0 0 0 0 . 5 0 4 0 0 . 5 0 8 0 0 . 5 1 2 0 0 . 5 1 6 0 0 . 5 1 9 9 0 . 5 2 3 9 0 . 5 2 7 9 0 . 5 3 1 9 0 . 5 3 5 90 . 1 0 . 5 3 9 8 0 . 5 4 3 8 0 . 5 4 7 8 0 . 5 5 1 7 0 . 5 5 5 7 0 . 5 5 9 6 0 . 5 6 3 6 0 . 5 6 7 5 0 . 5 7 1 4 0 . 5 7 5 30 . 2 0 . 5 7 9 3 0 . 5 8 3 2 0 . 5 8 7 1 0 . 5 9 1 0 0 . 5 9 4 8 0 . 5 9 8 7 0 . 6 0 2 6 0 . 6 0 6 4 0 . 6 1 0 3 0 . 6 1 4 10 . 3 0 . 6 1 7 9 0 . 6 2 1 7 0 . 6 2 5 5 0 . 6 2 9 3 0 . 6 3 3 1 0 . 6 3 6 8 0 . 6 4 0 6 0 . 6 4 4 3 0 . 6 4 8 0 0 . 6 5 1 70 . 4 0 . 6 5 5 4 0 . 6 5 9 1 0 . 6 6 2 8 0 . 6 6 6 4 0 . 6 7 0 0 0 . 6 7 3 6 0 . 6 7 7 2 0 . 6 8 0 8 0 . 6 8 4 4 0 . 6 8 7 90 . 5 0 . 6 9 1 5 0 . 6 9 5 0 0 . 6 9 8 5 0 . 7 0 1 9 0 . 7 0 5 4 0 . 7 0 8 8 0 . 7 1 2 3 0 . 7 1 5 7 0 . 7 1 9 0 0 . 7 2 2 40 . 6 0 . 7 2 5 7 0 . 7 2 9 1 0 . 7 3 2 4 0 . 7 3 5 7 0 . 7 3 8 9 0 . 7 4 2 2 0 . 7 4 5 4 0 . 7 4 8 6 0 . 7 5 1 7 0 . 7 5 4 90 . 7 0 . 7 5 8 0 0 . 7 6 1 1 0 . 7 6 4 2 0 . 7 6 7 3 0 . 7 7 0 4 0 . 7 7 3 4 0 . 7 7 6 4 0 . 7 7 9 4 0 . 7 8 2 3 0 . 7 8 5 20 . 8 0 . 7 8 8 1 0 . 7 9 1 0 0 . 7 9 3 9 0 . 7 9 6 7 0 . 7 9 9 5 0 . 8 0 2 3 0 . 8 0 5 1 0 . 8 0 7 8 0 . 8 1 0 6 0 . 8 1 3 30 . 9 0 . 8 1 5 9 0 . 8 1 8 6 0 . 8 2 1 2 0 . 8 2 3 8 0 . 8 2 6 4 0 . 8 2 8 9 0 . 8 3 1 5 0 . 8 3 4 0 0 . 8 3 6 5 0 . 8 3 8 91 0 . 8 4 1 3 0 . 8 4 3 8 0 . 8 4 6 1 0 . 8 4 8 5 0 . 8 5 0 8 0 . 8 5 3 1 0 . 8 5 5 4 0 . 8 5 7 7 0 . 8 5 9 9 0 . 8 6 2 11 . 1 0 . 8 6 4 3 0 . 8 6 6 5 0 . 8 6 8 6 0 . 8 7 0 8 0 . 8 7 2 9 0 . 8 7 4 9 0 . 8 7 7 0 0 . 8 7 9 0 0 . 8 8 1 0 0 . 8 8 3 01 . 2 0 . 8 8 4 9 0 . 8 8 6 9 0 . 8 8 8 8 0 . 8 9 0 7 0 . 8 9 2 5 0 . 8 9 4 4 0 . 8 9 6 2 0 . 8 9 8 0 0 . 8 9 9 7 0 . 9 0 1 51 . 3 0 . 9 0 3 2 0 . 9 0 4 9 0 . 9 0 6 6 0 . 9 0 8 2 0 . 9 0 9 9 0 . 9 1 1 5 0 . 9 1 3 1 0 . 9 1 4 7 0 . 9 1 6 2 0 . 9 1 7 71 . 4 0 . 9 1 9 2 0 . 9 2 0 7 0 . 9 2 2 2 0 . 9 2 3 6 0 . 9 2 5 1 0 . 9 2 6 5 0 . 9 2 7 9 0 . 9 2 9 2 0 . 9 3 0 6 0 . 9 3 1 91 . 5 0 . 9 3 3 2 0 . 9 3 4 5 0 . 9 3 5 7 0 . 9 3 7 0 0 . 9 3 8 2 0 . 9 3 9 4 0 . 9 4 0 6 0 . 9 4 1 8 0 . 9 4 2 9 0 . 9 4 4 11 . 6 0 . 9 4 5 2 0 . 9 4 6 3 0 . 9 4 7 4 0 . 9 4 8 4 0 . 9 4 9 5 0 . 9 5 0 5 0 . 9 5 1 5 0 . 9 5 2 5 0 . 9 5 3 5 0 . 9 5 4 51 . 7 0 . 9 5 5 4 0 . 9 5 6 4 0 . 9 5 7 3 0 . 9 5 8 2 0 . 9 5 9 1 0 . 9 5 9 9 0 . 9 6 0 8 0 . 9 6 1 6 0 . 9 6 2 5 0 . 9 6 3 31 . 8 0 . 9 6 4 1 0 . 9 6 4 9 0 . 9 6 5 6 0 . 9 6 6 4 0 . 9 6 7 1 0 . 9 6 7 8 0 . 9 6 8 6 0 . 9 6 9 3 0 . 9 6 9 9 0 . 9 7 0 61 . 9 0 . 9 7 1 3 0 . 9 7 1 9 0 . 9 7 2 6 0 . 9 7 3 2 0 . 9 7 3 8 0 . 9 7 4 4 0 . 9 7 5 0 0 . 9 7 5 6 0 . 9 7 6 1 0 . 9 7 6 72 0 . 9 7 7 2 0 . 9 7 7 8 0 . 9 7 8 3 0 . 9 7 8 8 0 . 9 7 9 3 0 . 9 7 9 8 0 . 9 8 0 3 0 . 9 8 0 8 0 . 9 8 1 2 0 . 9 8 1 72 . 1 0 . 9 8 2 1 0 . 9 8 2 6 0 . 9 8 3 0 0 . 9 8 3 4 0 . 9 8 3 8 0 . 9 8 4 2 0 . 9 8 4 6 0 . 9 8 5 0 0 . 9 8 5 4 0 . 9 8 5 72 . 2 0 . 9 8 6 1 0 . 9 8 6 4 0 . 9 8 6 8 0 . 9 8 7 1 0 . 9 8 7 5 0 . 9 8 7 8 0 . 9 8 8 1 0 . 9 8 8 4 0 . 9 8 8 7 0 . 9 8 9 02 . 3 0 . 9 8 9 3 0 . 9 8 9 6 0 . 9 8 9 8 0 . 9 9 0 1 0 . 9 9 0 4 0 . 9 9 0 6 0 . 9 9 0 9 0 . 9 9 1 1 0 . 9 9 1 3 0 . 9 9 1 62 . 4 0 . 9 9 1 8 0 . 9 9 2 0 0 . 9 9 2 2 0 . 9 9 2 5 0 . 9 9 2 7 0 . 9 9 2 9 0 . 9 9 3 1 0 . 9 9 3 2 0 . 9 9 3 4 0 . 9 9 3 62 . 5 0 . 9 9 3 8 0 . 9 9 4 0 0 . 9 9 4 1 0 . 9 9 4 3 0 . 9 9 4 5 0 . 9 9 4 6 0 . 9 9 4 8 0 . 9 9 4 9 0 . 9 9 5 1 0 . 9 9 5 22 . 6 0 . 9 9 5 3 0 . 9 9 5 5 0 . 9 9 5 6 0 . 9 9 5 7 0 . 9 9 5 9 0 . 9 9 6 0 0 . 9 9 6 1 0 . 9 9 6 2 0 . 9 9 6 3 0 . 9 9 6 42 . 7 0 . 9 9 6 5 0 . 9 9 6 6 0 . 9 9 6 7 0 . 9 9 6 8 0 . 9 9 6 9 0 . 9 9 7 0 0 . 9 9 7 1 0 . 9 9 7 2 0 . 9 9 7 3 0 . 9 9 7 42 . 8 0 . 9 9 7 4 0 . 9 9 7 5 0 . 9 9 7 6 0 . 9 9 7 7 0 . 9 9 7 7 0 . 9 9 7 8 0 . 9 9 7 9 0 . 9 9 7 9 0 . 9 9 8 0 0 . 9 9 8 12 . 9 0 . 9 9 8 1 0 . 9 9 8 2 0 . 9 9 8 2 0 . 9 9 8 3 0 . 9 9 8 4 0 . 9 9 8 4 0 . 9 9 8 5 0 . 9 9 8 5 0 . 9 9 8 6 0 . 9 9 8 63 0 . 9 9 8 7 0 . 9 9 8 7 0 . 9 9 8 7 0 . 9 9 8 8 0 . 9 9 8 8 0 . 9 9 8 9 0 . 9 9 8 9 0 . 9 9 8 9 0 . 9 9 9 0 0 . 9 9 9 0A r e a u n d e r t h e c u r v eZZ a Area under the curve Whereby, Shaded area = onetailed probability of occurence a = 1 – Shaded area Abcot Student t Distrbution example FDA requires pharmaceutical panies to perform extensive tests on all new drugs before they can be marketed to the public. The first phase of testing will be on animals, while the second