Can a pretest on mathematics skills predict success in a statistics course? The 82 students in an introductory statistics class took a pretest at the beginning of the semester. The least-squares regression line for predicting the score y on the final exam from the pretest score x was ŷ = 9.8 + 0.74x. The standard error of b1 was 0.41.
(a) Test the null hypothesis that there is no linear relationship between the pretest score and the score on the final exam against the two-sided alternative. (Round your test statistic to three decimal places and your P-value to four decimal places.)
t = | |
df = | |
P = |
Conclusion
We reject H0 at the 5% significance level.We do not reject H0 at the 5% significance level.
(b) Would you reject this null hypothesis versus the one-sided
alternative that the slope is positive? Explain your answer.
P =
Conclusion
We could reject H0 at the 5% significance level.We could not reject H0 at the 5% significance level.
Can a pretest on mathematics skills predict success in a statistics course? The 82 students in an...
Can a pretest on mathematics skills predict success in a statistics course? The 82 students in an introductory statistics class took a pretest at the beginning of the semester. The least-squares regression line for predicting the score y on the final exam from the pretest score x was ŷ = 9.4 + 0.78x. The standard error of b1 was 0.44. (a) Test the null hypothesis that there is no linear relationship between the pretest score and the score on the...
Can a pretest on mathematics skills predict success in a statistics course? The 82 students in an introductory statistics class took a pretest at the beginning of the semester. The least-squares regression line for predicting the score y on the final exam from the pretest score x was ŷ = 9.6 + 0.77x. The standard error of b1 was 0.42. (a) Test the null hypothesis that there is no linear relationship between the pretest score and the score on the...
The average final exam score for the statistics course is 82%. A professor wants to see if the average final exam score for students who are given colored pens on the first day of class is higher. The final exam scores for the 13 randomly selected students who were given the colored pens are shown below. Assume that the distribution of the population is normal. 89, 96, 70, 93, 95, 89, 100, 93, 71, 80, 91, 100, 75 What can...
The average final exam score for the statistics course is 74%. A professor wants to see if the average final exam score for students who are given colored pens on the first day of class is different. The final exam scores for the 16 randomly selected students who were given the colored pens are shown below. Assume that the distribution of the population is normal. 95, 87, 86, 87, 72, 69, 70, 99, 78, 78, 91, 69, 72, 73, 61,...
The average score for the statistics course is 39%. A professor wants to see if the average score for students who are given colored pens on the first day of class is larger. The scores for the 16 randomly selected students who were given the colored pens are shown below. Assume that the distribution of the population is normal. 44, 34, 32, 48, 42, 33, 40, 41, 50, 36, 50, 51, 43, 48, 47, 45 Copy to clipboard What can...
). Does a statistics course improve a student's mathematics skills, as measured by a national test? Suppose a random sample of 13 students takes the same national mathematics exam prior to enrolling in a stats course and just after completing the course. At a 1% level of significance determine whether the scores after the stats course are significantly higher than the scores before. Take the differences = before - after. Before After 430 465 485 475 520 535 360 410...
2:57:43 remainin The average final exam score for the statistics course is 82%. A professor wants to see if the average final exam score for students who are given colored pens on the first day of class is lower. The final exam scores for the 12 randomly selected students who were given the colored pens are shown below. Assume that the distribution of the population is normal. 82, 58, 82, 87, 74, 80, 71, 85, 79, 60, 65, 64 What...
The average test score for the statistics course is 81%. A professor wants to see if the average test score for students who are given colored pens on the first day of class is different. The test scores for the 12 randomly selected students who were given the colored pens are shown below. Assume that the distribution of the population is normal. 82, 59, 64, 78, 66, 73, 79, 61, 65, 54, 85, 58 What can be concluded at the...
Does a statistics course improve a student's mathematics skills, as measured by a national test? Suppose a random sample of 13 students takes the same national mathematics exam prior to enrolling in a stats course and just after completing the course. At a 1% level of significance determine whether the scores after the stats course are significantly higher than the scores before. Take the differences = before - after. Before 430 485 520 360 440 500 425 470 515 430...
Consider the following summary statistics, calculated from two independent random samples taken from normally distributed populations. Sample 1 Sample 2 x¯1=20.92 x¯2=26.80 s21=2.89 s22=3.81 n1=19 n2=15 Test the null hypothesis H0:μ1=μ2against the alternative hypothesis HA:μ1<μ2. a) Calculate the test statistic for the Welch Approximate t procedure. Round your response to at least 3 decimal places. b) The Welch-Satterthwaite approximation to the degrees of freedom is given by df = 27.983055. Using this information, determine the range in which the p-value...