Whitner Autoplex
The car dealership Whitner Autoplex sells both domestic and foreign cars. The probability of how many imported cars that are sold versus the number of domestic cars that were sold at the lot can be determined by many factors. This includes the prices that the vehicles are being sold at, which can affect the outcome because of the varying amounts of what people are willing to pay. The age of the buyer can also play a role in which type of car they purchase because of style preferences, and what they can afford to buy; or even what they think they can afford to buy. With the economy being where it is right now, most people are also looking at the benefits that the car may offer, such as having low gas mileage. The hypothesis test will determine the percentage of imported cars sold at the dealership. In the conclusion, the hypothesis will either be accepted or rejected after determining the actual probability. The level of significance to be used for this calculation is .05 or 95% confidence level.
Numerical Hypothesis
X1: Selling price in dollars
X2: Selling price in thousands of dollars
X3: Age of buyer
X4: 0=Domestic, 1=Imported 80 Autos Sold
Ho- p= .5 (The true hypothesis should be that out of the 80 cars that were sold, 40 of them should be imported cars.)
Ha- p < .5 or p > .5 (The actual statement states that out of the 80 cars sold, the number of imported cars will either be less than 40 or more than 40.)
Verbal Hypothesis
The percentage of imported cars sold at the Whitner Autoplex dealership should be 50%. Since the dealership carries both imported cars and domestic cars, the probability of the number of cars sold should be even, 50% imported -50% domestic. In the conclusion this hypothesis will be accepted or rejected.
We tested the Autoplex data to determine the 90% and 95% chance that the cars sold on the lot are imported. In Chart one shown below gives all the data to show the 95% chance that out of all the cars on the lot they were imported cars, chart two shows the 90% chance that out of all the cars sold on the lot they were imported. As we stated before our previous paper it is clear to see that imported cars out sell domestics by a long shot. With over 50 out of 80 of the cars being sold is imported leaving only 30 left of those being sold to domestic. First we calculated the averages the average price in dollars for both import and domestic cars sold at Autoplex. Being that we wanted to find out the 90% and 95% chance that the cars on the lot were imported instead of domestic we knew that our alpha we .05 and 0.1. We already knew that the total number of cars that were sold we 80 so, that was our N. From there we found the standard deviation for both imports which was 3558 and domestic was 4216.8. From here we just plugged the numbers into the formulas to find our standard deviation squared, our Tstar, TAlpha, and also the Pvalue. | Domestic | Imported | | X-Bar | 25,846.00 | 23,110 | | S | 3558 | 4216.8 | | N | 80 | 80 | | SP2 | 1009092998 | | | Alpha | 0.05 | 0.05 | Chart 1 | S2 | 12659364 | 17781402 | | Tstar | 0.54472899 | | | Talpha | 1.97509207 | | | PValue | 0.58670794 | | |

| Domestic | Imported | | X-Bar | 25,846.00 | 23,110 | | S | 3558 | 4216.8 | | N | 80 | 80 | | SP2 | 1009092998 | | | Alpha | 0.1 | 0.1 | Chart 2 | S2 | 12659364 | 17781402 | | Tstar | 0.54472899 | | | Talpha | 1.65455488 | | | Pvalue | 0.58670794 | | | From this data we can conclude that 90-95% of the cars sold on the lot of Autoplex are imported cars.