Researchers explored whether there were qualitative differences between students who were randomly assigned to take notes using pen and paper compared to students taking notes on a laptop (Mueller & Oppenheimer, 2014). They predicted that students who took notes using pen and paper would be more likely to put concepts into their own words and would produce less verbatim notes than the laptop group. The laptop group (n = 15) had a mean verbatim score of 16.2 (SS = 1000) and the pen and paper group (n = 12) had a mean verbatim score of 9.8 (SS = 925). Df=25. T-critical value= 2.0595. Do these data indicate a significant difference between the two groups in terms of note taking?   a. Compute the independent-samples test statistic. Show all work and formulas and circle your calculated test statistic. Round to two decimal places at each step.   b. State your decision regarding the null hypothesis.

Definition Definition Measure of central tendency that is the average of a given data set. The mean value is evaluated as the quotient of the sum of all observations by the sample size. The mean, in contrast to a median, is affected by extreme values. Very large or very small values can distract the mean from the center of the data. Arithmetic mean: The most common type of mean is the arithmetic mean. It is evaluated using the formula: μ = 1 N ∑ i = 1 N x i Other types of means are the geometric mean, logarithmic mean, and harmonic mean. Geometric mean: The nth root of the product of n observations from a data set is defined as the geometric mean of the set: G = x 1 x 2 ... x n n Logarithmic mean: The difference of the natural logarithms of the two numbers, divided by the difference between the numbers is the logarithmic mean of the two numbers. The logarithmic mean is used particularly in heat transfer and mass transfer. ln x 2 − ln x 1 x 2 − x 1 Harmonic mean: The inverse of the arithmetic mean of the inverses of all the numbers in a data set is the harmonic mean of the data. 1 1 x 1 + 1 x 2 + ...