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Homework Assignment 3: Independent Samples T-Test Please answer the following qu

ID: 3302662 • Letter: H

Question

Homework Assignment 3: Independent Samples T-Test Please answer the following questions as clearly and concisely as possible. You must show your work ta receive credit (i.e. don't just write down the answer you calculated in Excel). This homework assignment is due at the beginning of class on September 20 To complete this homework assignment, please consider the following table of length measurements of Daphnia (small planktonic animals that inhabit aquatic ecosystems) collected in June and September from a lake in the Upper Peninsula of Michigan September 1.17, 1.45, 1.43, 1.31, 1.12, 1.11, Month une Daphnia length 1.16, 1.13, 1.13, 1.15, 1.09, 0.85 1.31, 1.29, 1.38, 1.40, 1.24, 1.45, 1.29, 1.31, 1.42, 1.48, 1.26, 1.45, 1.04, 1.10, 1.48, 1.12 1.06, 1.12, 1.51, 1.13 1. Based on the results of a t-test, are Daphnia lengths different in June vs. September (assume two-tailed = 0.05 ? Be sure to state a calculated test statistic, critical t value from the Table, anaconcrsion to receive full credit!

Explanation / Answer


Two-sample T for june vs september

            N   Mean StDev SE Mean
june       16 1.208 0.168    0.042
september 16 1.289 0.154    0.039


Difference = (june) - (september)
Estimate for difference: -0.0813
95% CI for difference: (-0.1980, 0.0355)
T-Test of difference = 0 (vs ): T-Value = -1.42 P-Value = 0.165 DF = 29

Using data from columns 1 and 2

Not eq. vars: No Pool (and df calculated with Formula 9-1)

Alternative Hypothesis:
µ1 not equal µ2

Test Statistic, t: -1.4237
Critical t:        ±2.042914
P-Value:           0.1649

Degrees of freedom: 29.7765

95% Confidence interval:
-0.197839 < µ1-µ2 < 0.035339