Which of the following is correct about sample size? a. A sample size of 1,000 has the optimal balance of external validity and statistical accuracy. b. A large sample size still needs to be a random sample in order to be generalizable. A sample size of 1,000 allows for the most statistically accurate conclusions. d. A large sample size is more representative of the population than a small

Which of the following decrease(s) power in hypothesis testing?  A. Increasing the sample size. B. Decreasing αα level.  C. Increasing the population variance. D. Increasing the difference in the means of the two conditions in an independent-samples design. E. A and D F. B and C G. B and D H. C and D

The symbol x¯ represents the population mean of all possible sample means of size n. False True

Samples of airline departure times are obtained and compared to the scheduled departure times. Six major airlines are compared and their mean delay times are recorded. Identify the null and alternative hypotheses for applying an analysis of variance. Choose the correct answer below. OA. Ho: H₁ H₂ H3 H4 H5 H6 H₂: At least two of the means are equal. O B. Ho: At least one of the means is different from the others. Ha: H1 H2 H3 H4 H5=H6 OC. Ho: At least two of the means are equal. Ha: H1 H₂ H3 H4 H5 H6 O D. Ho: H₁ Ha: H1 O E. Ho: H₁ Ha: H1 OF. Ho: H₁ H₂ H3 H4 H5=H6 H₂ H3 H4 H5 H6 H₂ H3 H4 H5 H6 H2 H3 H4 H5=H6 H₂ H3 H4 H5=H6 Ha: At least one of the means is different from the others.

Provide an appropriate response. 1) A local supermarket claims that the waiting time for its customers to be served is the lowest in the area. A competitor's supermarket checks the waiting times at both supermarkets. The sample statistics are listed below. Test the local supermarket's hypothesis. Use a = 0.05. Local Supermarket n1 = 15 Competitor Supermarket n2 = 16 x2 = 5.6 minutes s2 = 1.0 minutes x1 = 5.3 minutes s1 = 1.1 minutes

A state-by-state survey found that the proportions of adults who are smokers in state A and state B were 22.9% and 19.3%, respectively. (Suppose the number of respondents from each state was 3000.) At a = 0.05, can you support the claim that the proportion of adults who are smokers is lower in state A than in state B? Assume the random samples are independent. Complete parts (a) through (e). (a) Identify the claim and state Ho and Ha. The claim is "the proportion of adults who are smokers in state A is the proportion of adults who are smokers in state B." Let p, and p2 be the two population proportions. State H, and Ha. Choose the correct answer below. O A. Ho: P1 = P2 Hạ: P1 # P2 O B. Ho: P1 P2 Ha: P1 SP2 D. Ho: P1 sP2 F. Ho: P1 2 P2 Ha: P1 > P2 Ha: P1 1.96 ОС. z2 -1.64 D. z 1.64 E. z - 1.96 (c) Find the standardized test statistic.

An elementary school teacher is interested in knowing if there is a significant difference in the average reading speed of fifth-grade boys and girls. She randomly selects 36 fifth grades boys and 36 fifth grade girls for the study. Each student is given several pages of the same book to read and the time it takes them to complete the reading is recorded in minutes.     Boys Girls Sample Size 36 36 Sample Mean reading speed (in minutes) 11 12 Population Variance 3 2 ​ ​The p-value is   a. 0.156   b. 0.0037   c. 0.336   d. 0.238

What is the key difference between a test of independence and a test of similarity and homogeneity? Select one: O a. The test of independence is a one-tailed test, whereas the test of homogeneity or similarity is a two-tailed test. O b. In a test of independence, the chi-squared test statistic has a different distribution than in a test of similarity. O c. In a test of independence, we only know the total sample size, whereas in a test of similarity or homogeneity, we know the sizes of the sampled groups we want to compare.

Homser Lake, Oregon, has an Atlantic salmon catch-and-release program that has been very successful. The average fisherman's catch has been ? = 9.0 Atlantic salmon per day. Suppose that a new quota system restricting the number of fishermen has been put into effect this season. A random sample of fishermen gave the following catches per day:12 6 11 12 5 0 27 8 7 6 3 12 12 I need help with (b) and the value of the sample test statistic

Violation of which assumption below for the two-factor ANVOA is not a cause for concern with large sample sizes?     a. The populations from which the samples are selected must have equal variances.   b. The populations from which the samples are selected must be normal.   c. A violation of any assumption below would be a concern, even with large sample sizes.   d. The observations within each sample must be independent.