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December 18, 2014

December 18, 2014

Posted by **Vannessa** on Tuesday, August 4, 2009 at 1:34pm.

Videotape 1: ¯x1 = 77.1 s1 = 7.8 n1 = 25

Videotape 2: x¯2 = 80.0 s2 = 8.1 n2 = 25

- statistics -
**MathMate**, Tuesday, August 4, 2009 at 2:49pmFirst make a hypothesis, for example,

H : the two tapes are equally effective, or

H : &mu_{1}= &mu_{2}

From the given data, calculate the t-statistic

t = (x̄2 - x̄1)/sqrt(s1²/n1+s2²/n2)

Calculate the degrees of freedom:

dof = ((s1²/n1) + (s2²/n2))²/((s1²/n1)²/n1 + (s2²/n2)²/n2)

Look up the Student's t-test values for the corresponding probability that they are equally effective. Use the two-tail test if there is no presumed domininance of one tape over the other.

A detailed numerical example is given in the following link:

http://www.jiskha.com/display.cgi?id=1249353992

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