A researcher wants to determine if there is a relationship between use of computer terminals (VDT-video display terminals) and miscarriages. An unpaired, case-control study is conducted. Of the cases...

A researcher wants to determine if there is a relationship between use of computer terminals (VDT-video display terminals) and miscarriages. An unpaired, case-control study is conducted. Of the cases (women with miscarriages), there were 30 women who used VDTs and 50 who did not. Among the controls, there were 90 women who used VDTs and 200 who did not. Compute chi-square, the odds ratio, and a 95% confidence interval for the odds ratio.