T-test for Two Independent Samples * This test is used when only two unrelated groups are being compared and the measurements are either interval or ratio. The two groups may or may not have the same number of samples. * The t-test for two independent groups involves testing whether or not there is a significant difference between the population means of the two groups. Consider a study wherein the effectiveness of banana leaves as an organic wrapper was compared to that of aluminum foil
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Two-Sample t-Tests Connie Tyrone Walden University August 24‚ 2013 Two Sample t-Tests With this assignment‚ we are told about Martha. Martha wants to see if her relaxing technique which involves visualization will be able to assist people suffering with mild insomnia to fall asleep faster. She randomly selects 20 insomnia patients to participate in her research. She assigns 10 from the group to participate in visualization therapy and 10 from the group receives no treatment. Martha then
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STUDY FINDINGS Before comparing the group means‚ assumptions for the paired sample t-test were evaluated and no violations were noted. Results from the paired sample t-test revealed statistically significant differences (p <= .05) in student competency self-assessment between the pretest and the posttest‚ and the posttest and the retrospective test on all 19 competencies (Table 2). Cohen’s effect size values ranging from 0.51 to 2.30 suggested moderate or high practical significance. These findings
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The T-TEST 1.0 INTRODUCTION The t-test was developed by W. S. Gossett‚ a statistician employed at the Guinness brewery. However‚ because the brewery did not allow employees to publish their research‚ Gossett’s work on the t-test appears under the name "Student". The t-test is sometimes referred to as "Student’s t-test." Gossett was a chemist and was responsible for developing procedures for ensuring the similarity of batches of Guinness. The t-test was developed as a way of measuring how closely
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Analysis - Summer 2013 Sample Test (Test 2‚ July 10th‚ 2013) Name: _______________________________ ID number: _____________________ Multiple Choice: Select the one correct (or best) answer. For questions with calculations‚ select the closest answer‚ as there may be differences due to rounding. No part credit. No penalty for guessing (so answer all questions!). 3 points for each. Transfer answers carefully to the Scantron. *Cell phone is required to be off during the test. A basic calculator is
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The T-Distribution and T-Test “In probability and statistics‚ Student ’s t-distribution (or simply the t-distribution) is a continuous probability distribution that arises when estimating the mean of a normally distributed population in situations where the sample size is small” (Narasimhan ‚ 1996). Similar to the normal distribution‚ the t-distribution is symmetric and bell-shaped‚ but has heavier tails‚ meaning that it is more likely to produce values far from its mean. This makes the t-distribution
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1. | Jill has called on Marcia’s Cosmetics for several years. She has always been friendly to Marcia but treated the other staff with indifference. When Marcia retired‚ Jill lost the account for what key reason(s)? | | a. | It was time for a new sales representative. | b. | No one knew her. | c. | No one was educated about her products. | d. | Jill’s communication style was different from the new buyer’s. | e. | Jill failed to develop good personal relationships with key people. |
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A one-sample test‚ also known as a goodness of fit test‚ shows whether the collected data is useful in making a prediction about the population. One sample tests are used when we have a single sample and wish to test the hypothesis that it comes from a specified population. In this case‚ the following questions are encountered: • Is there a difference between observed frequencies and the frequencies we would expect‚ based on some theory? • Is there a difference between observed and expected
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Assessing T-tests To clearly identify what a t-test accomplishes in descriptive statistics it is imperative to understand what a t-test represents. A “t-test is a parametric statistical test for comparing the means of two independent samples” (Plichta & Kelvin‚ 2013‚ p. 464). Gosset developed the t-test for use in quality control at the Guinness Brewery and published his works under the pen name “Student” (Plichta & Kelvin‚ 2013). T-tests use assumptions related to the underlying
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Sample Test for Content Development Section I Report writing (Time Duration: 180 minutes) Instructions: Choose any one Subject according to your academic background and compile a report of 825 words (3 pages). (For candidates with background of Stats or Finance‚ they are required to attempt both the sections A & B which are mentioned under their subject heads. Please make sure you have relevant software installed on your system‚ e.g. SPSS) Internet will be provided for assistance. However
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