Statistics Risk Rating - Insurance Classification Assignment

Data given(attached) is contains insurance classification, price and attributes of some cars in 1987. The aim of the study is to understand how insurance risk ratings and car attributes affect the price at which a car is sold. The variables in the data set are as follows:

1. Risk rating	-3, -2, -1, 0, 1, 2, 3.
2. Risk factor	Risky, neutral, safe
3. make	alfa-romero, audi, bmw, chevrolet, dodge, honda, isuzu, jaguar, mazda, mercedes-benz, mercury, mitsubishi, nissan, peugot, plymouth, porsche, renault, saab, subaru, toyota, volkswagen, volvo
4. fuel-type	diesel, gas.
5. aspiration	standard, turbo.
6. num-of-doors	four, two.
7. body-style	hardtop, wagon, sedan, hatchback, convertible.
8. drive-wheels	4wheel drive (4wd), forward wheel drive (fwd), rear wheel drive (rwd).
9. engine-location	front, rear.
10. wheel-base	continuous from 86.6 120.9.
11. length	continuous from 141.1 to 208.1.
12. width	continuous from 60.3 to 72.3.
13. height	continuous from 47.8 to 59.8.
14. curb-weight	continuous from 1488 to 4066.
15. engine-type	dohc, dohcv, l, ohc, ohcf, ohcv, rotor.
16. num-of-cylinders	eight, five, four, six, three, twelve, two.
17. engine-size	continuous from 61 to 326.
18. fuel-system	1bbl, 2bbl, 4bbl, idi, mfi, mpfi, spdi, spfi.
19. bore	continuous from 2.54 to 3.94.
20. stroke	continuous from 2.07 to 4.17.
21. compression-ratio	continuous from 7 to 23.
22. horsepower	continuous from 48 to 288.
23. peak-rpm	continuous from 4150 to 6600.
24. city-mpg	continuous from 13 to 49.
25. highway-mpg	continuous from 16 to 54.
26. price	continuous from 5118 to 45400.

We would like to understand how the variables interact with each other. Write a report that includes the following:

Calculate and interpret 95% confidence intervals of the proportion of cars that have four doors
Auto world magazine published an article on car efficiency in Dec 1987. The article claimed that the average highway mileage of cars in 1987 was higher than that in 1985. Test auto world’s hypothesis assuming that the average highway mileage in 1985 was 26 mpg.
Test the hypothesis that on average neutral-risk cars are more expensive than risky cars.
Test for the independence of the risk factor and wheel drive (fwd, rwd and 4wd)