The correct answer is True bacause the sampling distribution \(\frac{S_{1}^{2}}{S_{2}^{2}}\) is F distribution, dont is \(\chi^2\) distribution.

Question

asked 2021-01-05

Give full and correct answer for this questions
1) A t-test is a ?
2) Which of the following statement is true?
a)The less likely one is to commit a type I error, the more likely one is to commit a type II error,
b) A type I error has occurred when a false null hypothesis has been wrongly accepted.
c) A type I error has occurred when a two-tailed test has been performed instead of a one-tailed test,
d) None of the above statements is true.
3)Regarding the Central Limit Theorem, which of the following statement is NOT true?
a.The mean of the population of sample means taken from a population is equal to the mean of the original population.
b. The frequency distribution of the population of sample means taken from a population that is not normally distributed will approach normality as the sample size increases.
c. The standard deviation of the population of sample means is equal to the standard deviation of the, original population.
d. The frequency distribution of the population of sample means taken from a population that is not normally distributed will show less dispersion as the sample size increases.

asked 2021-01-06

a. Test for a difference in the means in the two populations using an \([\alpha={.05}{t}-{t}{e}{s}{t}.]\)

b. Place a 95% confidence interval on the difference in the means of the two populations.

c. Compare the inferences obtained from the results from the Wilcoxon rank sum test and the -test.

d. Which inferences appear to be more valid, inferences on the means or the medians?

asked 2020-12-28

Is statistical inference intuitive to babies? In other words, are babies able to generalize from sample to population? In this study,1 8-month-old infants watched someone draw a sample of five balls from an opaque box. Each sample consisted of four balls of one color (red or white) and one ball of the other color. After observing the sample, the side of the box was lifted so the infants could see all of the balls inside (the population). Some boxes had an “expected” population, with balls in the same color proportions as the sample, while other boxes had an “unexpected” population, with balls in the opposite color proportion from the sample. Babies looked at the unexpected populations for an average of 9.9 seconds (\(sd = 4.5\) seconds) and the expected populations for an average of 7.5 seconds (\(sd = 4.2\) seconds). The sample size in each group was 20, and you may assume the data in each group are reasonably normally distributed. Is this convincing evidence that babies look longer at the unexpected population, suggesting that they make inferences about the population from the sample? Let group 1 and group 2 be the time spent looking at the unexpected and expected populations, respectively. A) Calculate the relevant sample statistic. Enter the exact answer. Sample statistic: _____

B) Calculate the t-statistic. Round your answer to two decimal places. t-statistic = ___________

C) Find the p-value. Round your answer to three decimal places. p-value =__________

asked 2021-02-09

This problem demonstrates inference from two dependent (follow-up) samples using the data from the hypothetical study of new cases of tuberculosis (TB) before and after the vaccination was done in several geographical areas in a country in sub-Saharan Africa. Conclusion about the null hypothesis is to note the difference between samples.

The problem that demonstrates inference from two dependent samples uses hypothetical data from the TB vaccinations and the number of new cases before and after vaccination. \(\begin{array}{|c|c|} \hline Geographical\ regions & Before\ vaccination & After\ vaccination\\ \hline 1 & 85 & 11\\ \hline 2 & 77 & 5\\ \hline 3 & 110 & 14\\ \hline 4 & 65 & 12\\ \hline 5 & 81 & 10\\\hline 6 & 70 & 7\\ \hline 7 & 74 & 8\\ \hline 8 & 84 & 11\\ \hline 9 & 90 & 9\\ \hline 10 & 95 & 8\\ \hline \end{array}\)

Using the Minitab statistical analysis program to enter the data and perform the analysis, complete the following: Construct a one-sided \(\displaystyle{95}\%\) confidence interval for the true difference in population means. Test the null hypothesis that the population means are identical at the 0.05 level of significance.