In a random sample of 20 patients who visited the emergency room of hospital 1, a researcher found that the variance of the waiting time (in minutes) was 128.0. In a random sample of 15 patients in the emergency room of hospital 2, the researcher found the variance to be 178.8.

a) Can we infer at the 5% level of significance that the population variances differ? b) Estimate with 95% confidence the ratio of the two population variances.