Consider the following sample of observations on coating thickness for low-visco
ID: 3224680 • Letter: C
Question
Consider the following sample of observations on coating thickness for low-viscosity paint. 0.85 0.88 0.88 1.02 1.09 1.11 1.29 1.31 1.38 1.49 1.59 1.62 1.65 1.71 1.76 1.83 Assume that the distribution of coating thickness is normal a normal probability plot strongly supports this assumption (a) Calculate a point estimate of the mean value of coating thickness. (Round your answer to four decimal places.) 1.34125 State which estimator you used. (b) Calculate a point estimate of the median of the coating thickness distribution. (Round your answer to four decimal places.) 1.345 State which estimator you used and which estimator you might have used instead. (Select all that apply.) (c) Calculate a point estimate of the value that separates the largest 10% of all values in the thickness distribution from the remaining 90%. [Hint: Express what you are trying to estimate in terms of H and o.] ound your answer to four decimal placesExplanation / Answer
mean = 1.34125
std. dev. = 0.325861838
(c)
For 90%, z-value = 1.28
xbar = mean + z*sigma/sqrt(n)
xbar = 1.34125 + 1.28*0.3259/sqrt(16)
xbar = 1.4455
(d)
P(X<1.2) = P(z < (1.2-1.34125)/0.3259/sqrt(16)) = P(z < -1.7337) = 0.0415
(e)
Standard Error = sigma/sqrt(n)
SE = 0.3259/sqrt(16) = 0.0815