Sales records indicate that if DVD players are priced at $250, then a large store sells an average of 27 units per day. If they are priced at $100, then the store sells an average of 54 units per day. Find and graph the linear demand function for DVD sale

The demand function for DVD sales can be modeled using the linear equation y=mx+b, where y is the number of units sold per day, x is the price of the DVD player, m is the slope of the line, and b is the y-intercept. To find the slope, we use the two given points (250,27) and (100,54) using the formula m=(y2-y1)/(x2-x1). m = (54-27)/(100-250) = 27/150 = 0.18 To find the y-intercept, we can use one of the given points and solve for b. We will use (250,27). 27 = 0.18(250) + b b = -23 Therefore, the demand function for DVD sales is y = 0.18x - 23. To graph the demand function, we plot the two points given (250,27) and (100,54) and draw a line through them. The demand function is defined for any price of the DVD player because there is a linear relationship between price and the number of units sold. However, the practical range of prices could be limited by the market demand and competition.