10. A normal population with an unknown variance has a mean of 20. Is one likely...
4 pts Question 20 Consider taking random samples of size 50 from Population A with mean 15 and standard deviation 3 and random samples of size 75 from Population B with mean 10 and standard deviation 5. Use the provided formula sheet to calculate the standard error of the distribution of differences in sample means, T-58 Standard error = (Select) How many degrees of freedom should be used when conducting inference for ид - ив with samples of this size?...
1. A population of values follows a normal distribution with standard deviation 5 and unknown mean. A random sample of size 16 has mean 24. a) Write what each number represents. b) Find and interpret the 95% CI for the unknown population mean. c) Is 30 a plausible population mean? Explain.
(21) A sample of size 20 is drawn from a normal distribution with unknown variance and mean. The sample variance s2 = 0.012. Find a 95% two-sided confidence interval for the standard deviation o of the population. A. [0.0833,0.1600] B. (0.010,0.0130] C. (0.0069,0.0256] D. None of the above
11. Bonus problem (6 points) Assume X,...Xm come from a normal population with unknown variance σ' and Y1, Yn come from another normal population with unknown variance and the two samples are independent of each other. Write the 5 steps you will follow to test the hypotheses: Ho-1 Vs Hao #1 Make sure to specify the test statistic and the null distribution (don't forget degrees of freedom), and the rejection region. Hint Remember that-4 ~Xa-1 and-严 (m-1)s2 -X2-1, what do...
1- Suppose a simple random sample of sizen is drawn froma large population with mean u and standard deviation o. The sampling distribution of x has mean ug and standard deviation= 2- As the number of degrees of freedom in the t-distribution increase, the spread of the distribution 3- True or False: The value of to.10 with 5 degrees of freedom is greater than the value of to.10 with 10 degrees of freedom. 4- True or False: To construct a...
Bonus problem (6 points:) Assume X1, ... Xm come from a normal population with unknown variance oị and Y... Y come from another normal population with unknown variance o, and the two samples are independent of each other. Write the 5 steps you will follow to test the hypotheses: Hoi = 1 VS HQI # 1 Make sure to specify the test statistic and the null distribution (don't forget the degrees of freedom), and the rejection region. Hint: Remember that...
99 and standard deviation σ A population whose distribution is unknown has mean μ and a sample of size 26 is drawn from this population, then 1, a. The mean oJ a b. The standard error ot c. The distribution of A population whose distribution is unknown has mean μ = 99 and standard deviation σ = 7 and a sample of size 26 is drawn from this population, then 1, a. b. c. The mean of X= The standard...
Consider a normally distributed population with unknown variance ơ2. To test the null hypothesis that σ2 is equal to σ. we collect a sample of size n form the population and then calculate the sample variance S2. It is well known that we would fail-to-reject the null hypothesis if the following holds: 1-2n-1n-1 Note: χ2.v is such that P(x:Xp.v), and χ is a chi-squared random variable with v degrees of freedom. Use the above result to develop a hypothesis testing...
3. Testing a population mean The test statistic (Chapter 11) Aa Aa You conduct a hypothesis test about a population mean u with the following null and alternative hypotheses: Ho: u-25.8 H1: <25.8 Suppose that the population standard deviation has a known value of a observations, which provides a sample mean of % 30.7. 17.8. You obtain a sample of n =62 Since the sample size large enough, you assume that the sample mean X follows a normal distribution. Let...
Assume that with a sample size of 17 you conduct a test on a population mean with unknown standard deviation. What should the degrees of freedom of T0 be?