A laboratory in Washington is interested in finding the mean chloride level for a healthy resident in the state. A random sample of healthy residents has a mean chloride level of mEq/L. If it is known that the chloride levels in healthy individuals residing in Washington have a standard deviation of mEq/L, find a confidence interval for the true mean chloride level of all healthy Washington residents.
Carry your intermediate computations to at least three decimal places. Round your answers to one decimal place.
What is the lower limit of the 90% confidence level?
What is the upper limit of the 90% confidence level?
2007-05-01 08:54:02 · 3 answers · asked by Tammy 1 in Science & Mathematics ➔ Mathematics
If mean = mEq/L and sigma also = mEq/L, you have a bad frequency distribution curve. So your question is meaningless (infeasible) even if you did define the m, E, q, and L factors.
A standard normal curve with a mean = M, would have a six sigma plus spread from one tail to the other. The interval from the LH tail to the mean is 3 sigma wide; from the mean to the RH tail is another 3 sigmas wide.
In other words, if the mean M = mEq/L in a normal distribution (sample or population), its sigma has to be around sigma = mEq/3L so that the interval of the curve from left tail to right tail is 6 sigma = 6 mEq/3L = 2 mEq/L = 2M or twice the mean.
Assuming you boo booed the sigma, 95% CI runs from the mean to plus/minus 2 sigmas. So at 95% CI the lower limit is M - 2 sigmas = mEq/L - (2/3)mEq/L = (1/3)mEq/L; the upper limit is (5/3)mEq/L by similar computation but with the mean plus 2 sigmas. You need to look up the 90% CI sigma values in a table. But you know the answers will be close to the 1/3 and 5/3 values I gave you for a 95% CI off the top of my head.
2007-05-01 09:30:31 · answer #1 · answered by oldprof 7 · 0⤊ 0⤋
I give up. What's the answer?
2007-05-01 16:02:40 · answer #2 · answered by CMK 3 · 0⤊ 1⤋
im not sure
2007-05-01 15:57:12 · answer #3 · answered by lancasterangel03 2 · 0⤊ 1⤋