A researcher is interested in whether blind Braille readers could be taught to read faster using...

   

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A researcher is interested in whether blind Braille readers could be taught to read faster using the same techniques as sighted readers. He has blind adults complete a reading speed test before and after a six-week speed-reading course. In the beginning of the study, a randomly selected group of 121 blind Braille readers scored an average of 261 words per minute on the reading speed test. Since the sample size is larger than 30, the researcher can assume that the sampling distribution of Mp is normal. He plans to use a repeated-measures t-test. The researcher identifies the null and alternative hypotheses as: Ho: Po H: Po 0 0 Use the Distributions tool to find the critical region(s) for a = .05. The critical t-score, which is the value for t-spres that separates the tail(s) from the main body of the distribution and forms the critical region(s), is . (Hint: Remember to set the degrees of freedom on the tool and to consider whether this is a one-tailed or two-tailed test.) t Distribution Degrees of Freedom-115 .5000 .5000 .5000 2500 .2500 -4.0 -3.0 -2.0 -1.0 0.0 1.0 2.0 3.0 AA -0.677 0.000 0.677 After the speed-reading course, the blind Braille readers scored an average of 7 words per minute higher than before they began the speed-reading course. The standard deviation of the difference scores was s = 21. To calculate the t statistic, you must first calculate the estimated standard error. The estimated standard error is (Note: For best results, retain at least 4 decimal places from your calculation of the estimated standard error for use in calculating the t statistic.) Calculate the t statistic. The t statistic is in the critical region for a one-tailed conclude that the Use the tool to evaluate the null hypothesis. The t statistic hypothesis test. Therefore, the null hypothesis is speed-reading course increases speed of reading Braille. The researcher A researcher is interested in whether blind Braille readers could be taught to read faster using the same techniques as sighted readers. He has blind adults complete a reading speed test before and after a six-week speed-reading course. In the beginning of the study, a randomly selected group of 121 blind Braille readers scored an average of 261 words per minute on the reading speed test. Since the sample size is larger than 30, the researcher can assume that the sampling distribution of Mp is normal. He plans to use a repeated-measures t-test. The researcher identifies the null and alternative hypotheses as: Ho: Po H: Po 0 0 Use the Distributions tool to find the critical region(s) for a = .05. The critical t-score, which is the value for t-spres that separates the tail(s) from the main body of the distribution and forms the critical region(s), is . (Hint: Remember to set the degrees of freedom on the tool and to consider whether this is a one-tailed or two-tailed test.) t Distribution Degrees of Freedom-115 .5000 .5000 .5000 2500 .2500 -4.0 -3.0 -2.0 -1.0 0.0 1.0 2.0 3.0 AA -0.677 0.000 0.677 After the speed-reading course, the blind Braille readers scored an average of 7 words per minute higher than before they began the speed-reading course. The standard deviation of the difference scores was s = 21. To calculate the t statistic, you must first calculate the estimated standard error. The estimated standard error is (Note: For best results, retain at least 4 decimal places from your calculation of the estimated standard error for use in calculating the t statistic.) Calculate the t statistic. The t statistic is in the critical region for a one-tailed conclude that the Use the tool to evaluate the null hypothesis. The t statistic hypothesis test. Therefore, the null hypothesis is speed-reading course increases speed of reading Braille. The researcher