Suppose you have a sample of size 100 with a mean of 5 and a standard deviation of 2. Construct a 95% confidence interval for the population mean. 2. For a random sample of 50 measurements on the breaking strength of cotton threads, the mean breaking strength was found to be 210 grams and the standard deviation was 18 grams. Calculate a 90% confidence interval for the true mean breaking strength of cotton threads of this type.
Added by -Ngeles W.
Step 1
96. Margin of error = z * (σ / √n) Margin of error = 1.96 * (2 / √100) Margin of error = 1.96 * 0.2 Margin of error = 0.392 Show more…
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