Statistics homework-probability
Recall the car data set you identified in Week 2 from kelly blue book. You will want to calculate the average for your data set. (Be sure you use the numbers without the supercar outlier) Once you have the average count how many of your data points fall below the average. You will take that number and divide it by 10. This will be your p or “success” in your problem. Once you have p, calculate q.
If you were to find another random sample of 10 cars based on the same data, what is the probability that exactly 4 of them will fall below the average? Make sure you interpret your results.
If you were to find another random sample of 10 cars based on the same data, what is the probability that fewer than 5 of them will fall below the average? Make sure you interpret your results.
If you were to find another random sample of 10 cars based on the same data, what is the probability that more than 6 of them will fall below the average? Make sure you interpret your results.
If you were to find another random sample of 10 cars based on the same data, what is the probability that at least 4 of them will fall below the average? Make sure you interpret your results.
Sample Answer
Calculations
The average price of the cars in the data set is $25,000. There are 6 cars in the data set that are below the average price. This means that p, the probability of success, is 0.6. q, the probability of failure, is 0.4.
Probability that exactly 4 cars will fall below the average
The probability that exactly 4 cars will fall below the average is:
(0.6)^4(0.4)^6 = 0.021144
This means that there is a 0.21% chance that exactly 4 cars will fall below the average in a random sample of 10 cars.
Probability that fewer than 5 cars will fall below the average