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(21.23) A study of the effect of exposure to color (red or blue) on the ability

ID: 3311077 • Letter: #

Question

(21.23) A study of the effect of exposure to color (red or blue) on the ability to solve puzzles used 40 subjects. Half the subjects were asked to solve a series of puzzles while in a red-colored environment. The other half were asked to solve the same series of puzzles while in a blue-colored environment. The 20 subjects in the red-colored environment had a mean time for solving the puzzles of 9.61 seconds with standard deviation 3.47;the 20 subjects in the blue-colored environment had a mean time of 15.85 seconds with standard deviation 8.64 . The two-sample t statistic for comparing the population means has value (±0.001)

Explanation / Answer

The statistical software output for this problem is:

Two sample T summary hypothesis test:
1 : Mean of Population 1
2 : Mean of Population 2
1 - 2 : Difference between two means
H0 : 1 - 2 = 0
HA : 1 - 2 0
(without pooled variances)

Hypothesis test results:

Hence,

Two sample t - statistic = -2.997

Difference Sample Diff. Std. Err. DF T-Stat P-value 1 - 2 -6.24 2.0819522 24.973933 -2.997187 0.0061