value 12.00 points Exercise 8-7 Algo In order to estimate the mean 30-year fixed
ID: 3359369 • Letter: V
Question
value 12.00 points Exercise 8-7 Algo In order to estimate the mean 30-year fixed motgage rate for a sample of 25 recent loans is taken The averagecalculated fromthis sample is 6 20% It can be assumed that 30-year fixed mortgage rates are normally distributed with a standard deviation of 0 3% Compute 90% and 95% confidence intervals for the population mean 30-year fixed mortgage rate Use Tablet (Round intermediate calculations to 4 decimal places. Round "z-value" to 3 decimal places and final answers to 2 decimal places.Enter.your answers as percentages, not decimals.) horne loan in the United States, a random Confidence Level 90% 95% Confidence Interval %to % to Search the web and Windows LenovoExplanation / Answer
Solution:
Sample size = n = 25
Sample mean = M = 6.2
Sample standard deviation = s = 0.3
(a) 90% CI for mean:
CL = 0.90 then Z = 1.64
Now we calculate standard error
sM = (0.32/25) = 0.06
Formula of CI for mean is
= M ± Z(sM)
= 6.2 ± 1.64*0.06
= 6.2 ± 0.099
Hence 90% CI for population mean is (6.101%, 6.299%)
(b) 95% CI for mean:
CL = 0.95 then Z = 1.96
Now we calculate standard error
sM = (0.32/25) = 0.06
Formula of CI for mean is
= M ± Z(sM)
= 6.2 ± 1.96*0.06
= 6.2 ± 0.118
Hence 99% CI for population mean is (6.082%, 6.318%)
Done
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