Non parametric Statistics

2) Recent studies of the private practices of physicians who saw no Medicaid patients suggested that the median length of each patient visit was 22 minutes. It is believed that the median visit length in practices with a large Medicaid load is shorter than 22 minutes. A random sample of 20 visits in practices with a large Medicaid load yielded, in order, the following visit lengths: 9.4 13.4 15.6 16.2 16.4 16.8 18.1 18.7 18.9 19.1 19.3 20.1 20.4 21.6 21.9 23.4 23.5 24.8 24.9 26.8 Use the large sample approximation of the sign test to determine if there is sufficient evidence to conclude, at the 1% level of significance, that the average visit length in practices with a large Medicaid load is shorter than 22 minutes