Characteristics of ice-melt ponds. The National Snow and Ice Data Center (NSIDC) collected...

Characteristics of ice-melt ponds. The National Snow and Ice Data Center (NSIDC) collected data on 504 ice-melt ponds in the Canadian Arctic. The data are saved in the PONDICE file. One variable of interest to environmental engineers studying the ponds is the type of ice observed in each. Ice type is classified as first-year ice, multiyear ice, or landfast ice. The SAS summary table for the types of ice of the 504 ice-melt ponds is reproduced below.

a. Use a 90% confidence interval to estimate the proportion of ice-melt ponds in the Canadian Arctic that have first-year ice.

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b. Suppose environmental engineers hypothesize that 15% of Canadian Arctic ice-melt ponds have first-year ice, 40% have landfast ice, and 45% have multiyear ice. Test the engineers’ theory, using α = .01.