EXST 3201 Chapter : HW 5 Key

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azuremammoth471

15 Mar 2019

School

LSU

Department

Experimental Statistics

Course

EXST 3201

Professor

All

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Study time (x) 1 2 1 4 2 1 3 5 2 1 3 4. Test score (y) 6 6 5 8 4 3 5 7 5 3 5 6. Consider the above pairs of study time-test scores for 12 individuals: state the null and alternative hypotheses for testing if the correlation between study time and test score is significant (i. e. , different from 0). Ha: 0: find the critical value to compare this against, with a criterion of . 01. Cv = . 7079: compute the correlation coefficient (show all your work). 69: compare it to the critical value, and make your conclusion. Fail to reject the null: compute the effect size. 49: write up an apa formatted results section for your finding, following the example format from class. Study time and test scores were gathered on a group of 12 people. The pearson"s correlation coefficient was not significantly different from 0, r=. 69, n. s. (or p>. 05).

Related Questions

Hypothesis testing with ANOVA opinions about whether caffeine enhances test performance differ. You design a study to test the impact of drinks with different caffeine contents on students' test-taking abilities. You choose 21 students at random from your introductory psychology course to participate in your study. You randomly assign each student to one of three drinks, each with a different caffeine concentration, such that there are seven students assigned to each drink. You then give each of them a plain capsule containing the precise quantity of caffeine that would be consumed in their designated drink and have them take an arithmetic test 15 minutes later.

The students receive the following arithmetic test scores:

	Cola	Black Tea	Coffee
Caffeine Content (mg/oz)	2.9	5.9	13.4
	85	85	92	∑X² = 147,641
	86	89	87	G = 1,755
	82	82	80	N = 21
	75	75	89	k = 3
	66	88	96
	78	76	83
	87	82	92
	T₁ = 559	T₂ = 559	T₃ = 559
	SS₁ = 338.86	SS₂ = 338.86	SS₃ = 338.86
	n₁ = 7	n₂ = 7	n₃ = 7
	M₁ = 79.8571	M₂ = 79.8571	M₃ = 79.8571

1.) You plan to use an ANOVA to test the impact of drinks with different caffeine contents on students' test-taking abilities. What is the null hypothesis?

(a) The population mean test score for the cola population is different from the population mean test score for the black tea population.

(b) The population mean test scores for all three treatments are equal.

(d) The population mean test scores for all three treatments are not all equal.

2.) Calculate the degrees of freedom and the variances for the following ANOVA table:

Source	SS	df	MS
Between	-	-	-
Within	702.28	-	-
Total	973.14	-

The formula for the F-ratio is:

3.) Using words, the formula of the F-ratio can be written as:

4.) Using the data from the ANOVA table given, the F-ratio can be written as:

5.) Calculate for F-ratio:

6.) At the level of significance, what is your conclusion?

(a)You can reject the null hypothesis; you do not have enough evidence to say that caffeine affects test performance.

(b)You cannot reject the null hypothesis; caffeine does appear to affect test performance.

(c)You cannot reject the null hypothesis; you do not have enough evidence to say that caffeine affects test performance.

(d)You can reject the null hypothesis; caffeine does appear to affect test performance.

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EXST 3201 Chapter : HW 5 Key

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