The National Hurricane Center provides data that list the numbers of large (category 3, 4, or 5) hurricanes that have struck the United States, by decade since 1851 (www.nhc.noaa.gov/dcmi.shtml). The data are given below.

Recently, there's been some concern that perhaps the number of large hurricanes has been increasing. The natural null hypothesis would be that the frequency of such hurricanes has remained constant.
a) With 96 large hurricanes observed over the 16 periods, what are the expected value(s) for each cell?
b) What kind of chi-square test would be appropriate?
c) State the null and alternative hypotheses.
d) How many degrees of freedom are there?
e) The value of x2 is 12.67. What's the P-value?
f) State your conclusion

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Count Decade Cont Decade 1851-1860 6 1861-18701 1871-1880 7 1881-1890 5 1891-1900 8 1901-1910 4 1911-19207 1921-1930 5 1931-1940 1941-1950 10 1951-19609 1961-1970 6 1971-1980 1981-1990 4 1991-2000 2001-2010 7