We could use a -test to investigate

Who uses YouTube more: men or women? Based on two independent SRSs of 25 women and 28 men we will estimate the difference between their corresponding mean by means of a 90% CI. The value of the multplier should be: 

The number divided by helps us to quantify the

A two-way frequency table displays

You record the IQ scores of ten university students twice a year for four years and study their performance in relation to their gender and ethnicity. This is an example of:

For planning purposes you estimate that the mean operating costs for the company you work for in 2021 are $180,000 ± $20,000 with 95% confidence. Your supervisor is perplexed because she recalls you told her that the operating costs would be less than $185,000. You explain to her that:

The height of an adult man is normally distributed with mean 170 cm and sd 10 cm.

It is more likely to find a man whose height is less than 180cm vs finding a man whose height is greater than 160cm.

You conducted a HT for two independent means based on samples of size 30 and 40. Your test statistic was 0.70. Then