On the basis of extensive tests, the yield point of a particular type of mild steel-reinforcing bar is known to be normally distributed with o = 100. The composition of the bar has been slightly modified, but the modifica believed to have affected either the normality or the value of o. (a) Assuming this to be the case, if a sample of 36 modified bars resulted in a sample average yield point of 8448 Ib, compute a 90% CI for the true average yield point of the modified bar. (Round your answer decimal place.) Ib (b) How would you modify the interval in part (a) to obtain a confidence level of 96%? (Round your answer to two decimal places.) - --Select- should be changed to The sample size The standard deviation You may nee The sample mean e in the Appendix of Tables to answer this question. The value of z
Continuous Probability Distributions
Probability distributions are of two types, which are continuous probability distributions and discrete probability distributions. A continuous probability distribution contains an infinite number of values. For example, if time is infinite: you could count from 0 to a trillion seconds, billion seconds, so on indefinitely. A discrete probability distribution consists of only a countable set of possible values.
Normal Distribution
Suppose we had to design a bathroom weighing scale, how would we decide what should be the range of the weighing machine? Would we take the highest recorded human weight in history and use that as the upper limit for our weighing scale? This may not be a great idea as the sensitivity of the scale would get reduced if the range is too large. At the same time, if we keep the upper limit too low, it may not be usable for a large percentage of the population!
![On the basis of extensive tests, the yield point of a particular type of mild steel-reinforcing bar is known to be normally distributed with σ = 100. The composition of the bar has been slightly modified, but the modification is not believed to have affected either the normality or the value of σ.
(a) Assuming this to be the case, if a sample of 36 modified bars resulted in a sample average yield point of 8448 lb, compute a 90% CI for the true average yield point of the modified bar. (Round your answers to one decimal place.)
(______, ______) lb
(b) How would you modify the interval in part (a) to obtain a confidence level of 96%? (Round your answer to two decimal places.)
The value of z should be changed to ______.
You may need to use the z table in the Appendix of Tables to answer this question.
There is a dropdown menu with the following options:
- ---Select---
- The sample size
- The standard deviation
- The sample mean
- The value of z
[Visual Explanation]
The image displays a task about computing confidence intervals for the average yield point of modified steel-reinforcing bars. It provides specific numeric data such as the sample size, standard deviation, and mean needed for calculation. There's also a reference to an appendix table for further information along with interactive input fields for user responses.](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2Fc45072c9-820f-4d06-bb43-63ea77dc776c%2Fe0699a78-ddd5-419d-ac63-b8da2f3c894c%2Fb5chck8_processed.png&w=3840&q=75)
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