To solve the given problem, we need to follow these steps:
(a) Calculate the sample mean and sample standard deviation for the given salaries.
(b) Apply a 6% raise to each salary and then calculate the new sample mean and sample standard deviation.
(c) Convert each salary to a monthly salary by dividing by 12, and then calculate the sample mean and sample standard deviation for the revised data set.
Given the salaries in thousands of dollars:
\[ \{52, 38, 50, 58, 40, 40, 52, 38, 50, 27, 58, 52, 43\} \]
The sample mean (\(\bar{x}\)) is calculated as:
\[ \bar{x} = 46.0 \]
The sample standard deviation (\(s\)) is calculated as:
\[ s = 9.1196 \]
Each salary is increased by 6%, resulting in the revised salaries:
\[ \{55.12, 40.28, 53.00, 61.48, 42.40, 42.40, 55.12, 40.28, 53.00, 28.62, 61.48, 55.12, 45.58\} \]
The new sample mean (\(\bar{x}\)) is:
\[ \bar{x} = 48.76 \]
The new sample standard deviation (\(s\)) is:
\[ s = 9.6668 \]
Each original salary is divided by 12 to convert to monthly salaries:
\[ \{4.3333, 3.1667, 4.1667, 4.8333, 3.3333, 3.3333, 4.3333, 3.1667, 4.1667, 2.2500, 4.8333, 4.3333, 3.5833\} \]
The sample mean (\(\bar{x}\)) for the monthly salaries is:
\[ \bar{x} = 3.8333 \]
The sample standard deviation (\(s\)) for the monthly salaries is:
\[ s = 0.7600 \]
\(\boxed{\bar{x} = 3.8}\)