Suppose you used a 10-point rating scale to measure intention-to-buy (1 = definitely would not buy and 10 = definitely would buy). If a group of 40 males had a mean of 7 and a standard deviation of 2.5, while a group of 35 females had a mean of 5 and a standard deviation of 1.4, then the standard error of the difference between the means would be approximately:
A) 0.48.
B) 2.06.
C) 0.23.
D) 4.25.

Question

Quizplus · Accepted Answer

The standard error of the difference between the means (SED) can be calculated using the formula: SED = sqrt[(s1^2 / n1) + (s2^2 / n2)], where s1 and s2 are the standard deviations of the two groups, and n1 and n2 are the sample sizes of the two groups. Plugging in the values given: SED = sqrt[(2.5^2 / 40) + (1.4^2 / 35)] = sqrt[(6.25 / 40) + (1.96 / 35)] = sqrt[0.15625 + 0.056] = sqrt[0.21225] ≈ 0.46. The closest answer provided is 0.48, option A.

Suppose You Used a 10-Point Rating Scale to Measure Intention-To-Buy