Question

1) state your hypotheses; 2) draw a graph showing the critical z-scores and the rejection region; 3) calculate z-obtained; 4) make a conclusion.

Are there gender differences in the time spent using on social media? A time-tracking software was used to determine the average time on social media websites in a random sample of 86 men and 96 women. Men, on average, spent 52 minutes per day on social media websites, with the standard deviation of 25. Women, on average, spent 108 minutes per day on social media websites, with a standard deviation of 18. Use α=0.05.

Answer 1

1) H₀:

   H₁:

2) At alpha = 0.05, the critical values are z_0.025 = +/- 1.96

Reject H₀, if z < -1.96 or z > 1.96

3) The test statistic z = ()/

                                 = (52 - 108)/sqrt((25)^2/86 + (18)^2/96)

   = -17.17

4) Since the test statistic value is less than the negative critical value(-17.17 < -1.96), so we should reject the null hypothesis.

So at 0.05 significance level we can conclude that there is a gender differences in the time spent using on social media.