The owner of Restaurant X is interested in determining the relationship between weekly advertising expenditure and sales (both in thousands of dollars). She takes a random sample of seven restaurants. The data and excel output are displayed below

Advertising Expenditure ($'000)	1	2	4	6	10	14	20
Sales ($'000)	19	32	44	40	52	53	54

How would we work out what is the least squares regression line to predict sales based on advertising expenditure? and what the model predict the sales when the weekly advertising expenditure is $5,000?