Paste
Copy
Cut


Options

This problem has been solved!

You'll get a detailed solution from a subject matter expert that helps you learn core concepts.

See Answer

  • Question: 1. The tensile strength (in KSI) of stainless-steel wires made by an existing process is normally distributed with a mean of 350 KSI. A batch of wires is made by a new process, and a random sample consisting of 25 measurements gives an average strength of 353 KSI and standard deviation of 5 KSI. Compute a 95% confidence interval estimate for the mean

    1. The tensile strength (in KSI) of stainless-steel wires made by an existing process is normally distributed with a mean of 350 KSI. A batch of wires is made by a new process, and a random sample consisting of 25 measurements gives an average strength of 353 KSI and standard deviation of 5 KSI. Compute a 95% confidence interval estimate for the mean strength of stainless-steel wires made by the new process.

    2. South African mathematician John Edmund Kerrich was known for his coin tossing experiment. While a prisoner of war during World War II, he tossed a coin 10,000 times and
    obtained 5,067 heads. Give a 90% confidence interval estimate for the true proportion of heads out of all coin tosses. Based on the computed interval, can we say that Kerrich’s coin
    is not fair?

    3. The following data represent the length of time, in days, to recovery of patients randomly treated with one of two medications to clear up several bladder infections: Compute a 90%
    confidence interval estimate for the difference of means. Compute a 90% confidence interval estimate for the difference of means.

    student submitted image, transcription available below

    4. A study published in Chemosphere reported the levels of the dioxin TCDD of 20 Massachusetts Vietnam veterans who were possibly exposed to Agent Orange. The TCDD levels in plasma and in fat tissue are listed in the following table

    student submitted image, transcription available below

    Assuming the distribution of the differences to be approximately normal, find a 95% confidence interval for µ1 - µ2, where µ1and µ2 represent the true mean TCDD levels in plasma and fat tissue, respectively.

    Show transcribed image text
  • Chegg Logo
    Here’s the best way to solve it.
    Solution

    Question 1. The given data are as follows: Population mean () of the existing process is 350 Sample size (n) is 25 Sam…

    View the full answer
    answer image blur
Transcribed image text:
Medication 1 ni = 14 X = 17 sæ = 1.5 Medication 2 n2 = 16 y = 19 s} = 1.8 4.9 3.1 TCDD TCDD TCDD TCDD Levels in Levels in Levels in Levels in Veteran Plasma Fat Tissue di Veteran Plasma Fat Tissue d; 1 2.5 -2.4 11 6.9 7.0 -0.1 2 5.9 -2.8 12 3.3 2.9 0.4 3 2.1 4.4 -2.3 13 4.6 4.6 0.0 4 3.5 6.9 -3.4 14 1.6 1.4 0.2 5 3.1 7.0 -3.9 15 7.2 7.7 -0.5 6 1.8 4.2 -2.4 16 1.8 1.1 0.7 7 6.0 10.0 -4.0 17 11.0 9.0 8 3.0 5.5 -2.5 18 2.0 2.5 -0.5 9 36.0 41.0 -5.0 19 0.2 10 4.7 0.3 20 4.1 2.5 1.6 Source: Schecter, A. et al. "Partitioning of 2,3,7,8-chlorinated dibenzo-p-dioxins and dibenzofurans between adipose tissue and plasma lipid of 20 Massachusetts Vietnam veterans, Chemosphere, Vol. 20, Nos. 7-9, 1990, pp. 864-965 (Tables I and II). 20.0 2.5 2.3