Mean Profit
a Report Stated That the Mean Profit Margin

Short Answer

Mean Profit
A report stated that the mean profit margin of 1000 publicly held corporations is 7.5 percent and the standard deviation is 5.1 percent.Profit margins appear normally distributed.A financial analyst sampled 100 of these companies to test whether or not the mean and standard deviation are as stated.The sample results were: $$\begin{array} { | l | c | } \hline \text { Category } & \text { Frequency } \\\hline \text { Under } 2 & 6 \\2 - \text { under } 6 & 32 \\6 \text {-under } 10 & 34 \\10 \text {-under } 14 & 14 \\14 \text {-under } 18 & 6 \\18 \text { or more } & 8 \\\hline\end{array}$$
-A test for independence is applied to a contingency table with 4 rows and 5 columns for two nominal variables.Calculate the degrees of freedom for this test.