Researchers measured the amount of plasma carotenoids (in micrograms per milliliter) of male and female zebra finches. Here are the summary statistics from the study: \[\begin{array} { | l | l | l | l | } \hline \text { Sex } & \boldsymbol { n } & \text { Mean } & \text { Standard Error } \\ \hline \text { Males } & 50 & 31.77 & 1.85 \\ \hline \text { Females } & 52 & 29.74 & 2.02 \\ \hline \end{array}\] Do male and female zebra finches differ in their plasma carotenoid levels? To answer this question, the researchers tested the following hypotheses: ? H0: ?M=?F versus ?M??F What can we conclude at significance level 5%?

A) Reject the alternative hypothesis B) Fail to reject the alternative hypothesis C) Reject the null hypothesis D) Fail to reject the null hypothesis A) Reject the alternative hypothesis B) Fail to reject the alternative hypothesis C) Reject the null hypothesis D) Fail to reject the null hypothesis

A new diet has been developed for raising beef cows. Two random samples of size 9 are independently selected, and one is given the standard diet while the other is given the new diet. After 18 weeks, the weight gain was measured for each cow. It was found that x̄1= 30 with S1= 8 and x̄2= 26 with S2= 6. Let μ1 and μ2 represent the mean weight gains we would observe for the entire population of beef cows when on, respectively, a new diet and a standard diet. Assume that two-sample t procedures are safe to use. Suppose the researcher had wished to test the following hypotheses: H0: μ1 = μ2 versus Ha: μ1 > μ2 What is the P-value for the test of these hypotheses?

A) Greater than 0.10 B) Between 0.10 and 0.05 C) Between 0.05 and 0.01 D) Less than 0.01 A) Greater than 0.10 B) Between 0.10 and 0.05 C) Between 0.05 and 0.01 D) Less than 0.01

Researchers examined the bill color (in hue degree) of male and female zebra finches. Here are some summary statistics from the study: \[\begin{array} { | l | l | l | l | } \hline \text { Sex } & \boldsymbol { n } & \text { Mean } & \text { Standard Error } \\ \hline \text { Males } & 59 & 2.91 & 0.19 \\ \hline \text { Females } & 60 & 7.42 & 0.32 \\ \hline \end{array}\] We wish to address the question, How different are male and female zebra finches in bill color? What is a 95% confidence interval for the difference in mean bill color ?F-?M (in hue degree)?

A) 4.41 to 4.61 B) 3.77 to 5.25 C) 3.23 to 5.79 D) 1.20 to 10.22 A) 4.41 to 4.61 B) 3.77 to 5.25 C) 3.23 to 5.79 D) 1.20 to 10.22

Some chronic conditions produce episodes of severe flare-ups ("active" stage) between healthy periods ("inactive" stage). The active stage often necessitates immediate medical treatment. Researchers looked for biomarkers that might help identify these active stages. Here are data on the relative abundance of the protein BPG0199 in two independent random samples of men with the same chronic condition, 7 men in the active phase and 9 men in the inactive phase: \[\begin{array} { | l | l | } \hline \text { Active } & \text { Inactive } \\ \hline 2.6 & 1.2 \\ \hline 2.7 & 2.1 \\ \hline 2.0 & 1.8 \\ \hline 2.4 & 1.5 \\ \hline 1.9 & 1.9 \\ \hline 1.4 & 3.2 \\ \hline 1.8 & 1.3 \\ \hline & 1.9 \\ \hline & 1.6 \\ \hline \end{array}\] We want to know if there is a significant difference in the relative abundance of the protein BPG0199 between men in the active stage and men in the inactive phase. Therefore, we test the following hypotheses: ? H0: ?A= ?1 versus Ha: ?A? ?1 Which assumption must be TRUE for this test result to be correct?

A) The same individuals must be measured during an active phase and during an inactive phase. B) The population standard deviations must be equal. C) The sample standard deviations must be similar. D) The population distributions must be roughly Normal. A) The same individuals must be measured during an active phase and during an inactive phase. B) The population standard deviations must be equal. C) The sample standard deviations must be similar. D) The population distributions must be roughly Normal.

A study examined the effect of protein consumption on weight gain in rats. Investigators obtained 14 female rats and randomly assigned 7 of them to a low-protein diet and the other 7 in a high-protein diet. After 60 days, the weight gained by each rat was recorded (in grams). Here are the summary findings, displayed as "mean (standard deviation)": \[\begin{array}{l} \begin{array} { l l } \text { Low-Protein Diet}&\text { High-Protein Diet}\\ 101.3(20.6)&127.5(21.1) \end{array} \end{array}\] Researchers want to know if the amount of protein in the rats' diet significantly affects their weight gain. Based on the data, what is the absolute numerical value of t statistic for the appropriate test?

A) 1.25 B) 2.35 C) 6.04 D) 13.10 A) 1.25 B) 2.35 C) 6.04 D) 13.10

A new diet has been developed for raising beef cows. Two random samples of size 9 are independently selected, and one is given the standard diet while the other is given the new diet. After 18 weeks, the weight gain was measured for each cow. It was found that x̄1= 30 with S1= 8 and x̄2= 26 with S2= 6. Let μ1 and μ2 represent the mean weight gains we would observe for the entire population of beef cows when on, respectively, a new diet and a standard diet. Assume that two-sample t procedures are safe to use. About which of the following characteristics would it have been most important that the researchers be blind during the experiment?

A) Whether the cows were male or female B) The purpose of the research C) The initial weight of the cows D) Which diet the cows received A) Whether the cows were male or female B) The purpose of the research C) The initial weight of the cows D) Which diet the cows received

Some chronic conditions produce episodes of severe flare-ups ("active" stage) between healthy periods ("inactive" stage). The active stage often necessitates immediate medical treatment. Researchers looked for biomarkers that might help identify these active stages. Here are data on the relative abundance of the protein BPG0235 in two independent random samples of men with the same chronic condition, 7 men in the active phase and 9 men in the inactive phase: \[\begin{array} { | l | l | } \hline \text { Active } & \text { Inactive } \\ \hline 1.0 & 1.1 \\ \hline 1.0 & 0.9 \\ \hline 1.0 & 0.5 \\ \hline 1.2 & 0.9 \\ \hline 1.2 & 1.0 \\ \hline 1.3 & 1.0 \\ \hline 1.0 & 0.8 \\ \hline & 0.7 \\ \hline & 1.1 \\ \hline \end{array}\] We want to know if there is a significant difference in the relative abundance of the protein BPG0235 between men in the active stage and men in the inactive phase. Therefore, we test the following hypotheses: ? H0: ?A= ?1 versus Ha: ?A? ?1 What is the absolute numerical value of the two-sample t statistic?

A) 13.7 B) 0.22 C) 3.41 D) 2.58 A) 13.7 B) 0.22 C) 3.41 D) 2.58

Researchers measured the amount of plasma carotenoids (in micrograms per milliliter) of male and female zebra finches. Here are the summary statistics from the study: \[\begin{array} { | l | l | l | l | } \hline \text { Sex } & \boldsymbol { n } & \text { Mean } & \text { Standard Error } \\ \hline \text { Males } & 50 & 31.77 & 1.85 \\ \hline \text { Females } & 52 & 29.74 & 2.02 \\ \hline \end{array}\] Do male and female zebra finches differ in their plasma carotenoid levels? To answer this question, the researchers tested the following hypotheses: ? H0: ?M=?F versus ?M??F What is the numerical value of the two-sample t statistic?

A) 0.46 B) 0.74 C) 3.41 D) 5.30 A) 0.46 B) 0.74 C) 3.41 D) 5.30

Researchers measured the amount of plasma carotenoids (in micrograms per milliliter) of male and female zebra finches. Here are the summary statistics from the study: \[\begin{array} { | l | l | l | l | } \hline \text { Sex } & \boldsymbol { n } & \text { Mean } & \text { Standard Error } \\ \hline \text { Males } & 50 & 31.77 & 1.85 \\ \hline \text { Females } & 52 & 29.74 & 2.02 \\ \hline \end{array}\] Do male and female zebra finches differ in their plasma carotenoid levels? To answer this question, the researchers tested the following hypotheses: ? H0: ?M=?F versus ?M??F What is the P-value for the test?

A) Greater than 0.10 B) Between 0.10 and 0.05 C) Between 0.05 and 0.01 D) Less than 0.01 A) Greater than 0.10 B) Between 0.10 and 0.05 C) Between 0.05 and 0.01 D) Less than 0.01