Question

Determinism each situation is likely to be normally distributed, normally distributed, skewed left, or skewed right.

a. The age at which people died in the U.S.

b. Selling prices of cars in 2019

c. The number of pets owned by students at your school.

d. The height of all adult females in Connecticut

(NOT A MULTIPLE CHOICE)​

Answer 1

Answers

• a) Skewed left
• b) Skewed right
• c) Normally distributed (symmetrical)
• d) Normally distributed (symmetrical)

==============================================================

Explanations:

• a) It's a very unfortunate part of life that everyone dies, and some do earlier than others. In general and on a grand scale of things, the older generations tend to die more frequently compared to the younger generations. In other words, an 90 year old man is more likely to die than say a 20 year old man. This is assuming that they both live in the same environment with other factors held constant as well. Because the older generation dies more frequently, this means we have the main cluster to the right (where the ages are older) and a long tail stretching to the left. The tail is the set of outliers of people who died at a fairly young age. Again, I'm not saying that young people don't die, but I'm saying that they don't die as much compared to older people. This tail on the left tells us we have negatively skewed data.
• b) Most cars are priced low so that people can afford them. So the main cluster is to the left while we have outliers to the right. The outliers to the right represent very expensive luxury cars. The outliers on the right side pull on the right tail to make it skewed to the right. We consider this positively skewed. In contrast, the one for part (a) was negatively skewed. Think of the positive and negative directions on the x axis to help figure out which direction things are being skewed in.
• c) Some people have a lot of pets, while others have few or none at all. In the middle is some average number where the highest peak is located. The distribution is fairly normal as with anything scattered about on average.
• d) Similar to part (c). There are some very short women, and some are very tall, but the majority are within some range of the average height. Doing a dot plot or a histogram of the distribution help leads to an approximately normal distribution, which is symmetric.