Question

The following data shows the hours worked by employees at a McDonalds and the number of dollars that they earned that day. Hours worked Pay dollars 8 68 7 59.5 8 68 5 42.5 10 85 8.5 72.25 7.5 63.75 9 76.5 Average: 7.875 66.9375 Standard Deviation 1.482035 12.5973 Correlation 1 a)Draw a scatterplot that represents this data. Draw an estimate for the line of least fit on the scatterplot as well. b) Use technology to find the least squares regression line. Write the equation below. c) Use the equation from the previous question to find how much a person would be paid for a 12 hour shift. Show your work.

Answer 1

a) We can use excel to draw the scatter plot :

Select both data set ---> Go to Insert menu ---> Charts ---> Scatter plot.

b)

Lease square regression equation.

Y = b₀ + b₁ *x

Or Pay dollars = b₀ + b₁ * Hours

b₀ is Intercept , we can find intercept using excel function =INTERCEPT( Y data set column range, x data set column range )

b₁ is Slope , we can find slope using excel function =SLOPE( Y data set column range, x data set column range )

Least squares regression line :

Pay dollars = 8.5*hours

c) We are given hours = 12 and asked to predict Pay dollars using above equation of regression line

Pay dollars = 8.5*12

Pay dollars = 102

So  a person would be paid 102 dollars for a 12 hour shift.