Question

Moving to another question will save this response. gestion 8 A company sampled 80 employees whose salaries are summarized in the frequency distribution below. Find the standard deviation Salary (dollars) Employees 5,001-10,000 12 10,001-15,000 13 15,001-20,000 14 20,001-25,000 19 25,001-30,000 22 $7887.30 $7105.67 $7461.00 $7674.10 A Moving to another question will save this response MacBook Air 000 esc 20 FI F4 F2 F3

Answer 1

Solution:

Option b) Standard deviation is $ 7105.67

Procedure:

Step1) Find midpoint ( class mark) of all the class intervals using the formula,

x= (upper class limit+ lower class limit) /2

Step2)Calculate the number of samples of a data set by summing up the frequencies.

Step3)Find the mean for the grouped data by dividing the addition of multiplication of each group mid-point and frequency of the data set by the number of samples.

ie, xbar = Sum( f*x) /sum( f)

Step 4) Calculate the variance by using the formula,

Variance= sum(f( x- xbar) ^2) /sum(f)

Step 5) Estimate standard deviation by taking square root of the variance.