Named tropical cyclones 2017. It has been suggested that global climate change may be affecting the frequency of tropical storms. The data here show the number of tropical cyclones (including hurricanes) assigned official names by the National Hurricane Center. Is there evidence of a change? (Data extracted from Hurricane history)

1997–2006 2007–2017 9, 14, 16, 19, 17, 14, 21, 17, 31, 10 17, 17, 11, 21, 20, 19, 15, 9, 12, 16, 14

a) Write the null and alternative hypotheses.

b) Are the conditions for hypothesis testing satisfied?

c) If so, test the hypothesis.