Stat-1 Essay Example | Topics and Well Written Essays - 750 words

Stat-1 - Essay Example d) No, the budgets for such home improvement jobs must be not exactly normally distributed for the confidence interval I obtained in part (b) to be approximately correct. Since, the sample is random and is greater than 30 (n≠¥30) i.e. large enough therefore we can apply Central Limit Theorem for a Mean, therefore we can assume budgets for such home improvements jobs are approximately normally distributed. The 95.44% confidence interval for ÃŽ ¼ ($2,483.04 The typing skills of recent applicants are not good, because 99% confidence interval for the mean number of words input per minute by recent applicants lies entirely below 70. It should be above or approximately equal to 70. b) The 95% confidence interval for the mean calcium intake, ÃŽ ¼, of all adults with incomes below the poverty level is 860.54 mg b) The confidence interval found in part (a) is shorter than the one in Exercise 8.32 because in this case Sample standard deviation 171.99 mg is too small as compared to population standard deviation 188mg. However, in general, using t increases the confidence level slightly as compared to using z. b) The 90% confidence interval for the mean plasma level of adrenomedullin, ÃŽ ¼ for all women with recurrent pregnancy loss is 5.080 < ÃŽ ¼ < 6.120 pmol/l. There is a probability of 0.90 that an interval constructed this way will contain the mean plasma level of adrenomedullin, ÃŽ ¼ for all women with recurrent pregnancy