H3.1
In a symmetric, unimodal distribution, about two-thirds of the observations are where?
Approximately two-thirds of the observations in a symmetric, unimodal distribution are within one standard deviation of the mean.
A sociologist says, "Typically, men in a certain country still earn more than women." What does this statement mean?
In a distribution of values, the typical value is given by the mean. In this case, the average salary of a man is higher than that of a woman, so when comparing the distribution of men's salaries to women's salaries, the center of the distribution for men is greater than the center of the distribution for the women.
Suppose you have a data set with the weights of all members of a high school soccer team and all members of a high school academic decathlon team (a team of students selected because they often answer quiz questions correctly). Which team do you think would have a larger standard deviation of weights? Explain.
The academic decathlon team would have a larger standard deviation of weights. Academics don't require a specific weight to succeed, so the distribution of weights should mirror that of the general population.
The ____ is another term for the arithmetic average
The mean is another term for the arithmatic average. It can be thought of as the balancing point of a distribution of data.
The mean of a collection of data is located at the ______ of a distribution of data.
The mean of a collection of data is located at the "balancing point" of a distribution of data.
The mean represents the typical value in a set of data for what type of distribution?
The mean represents the typical value in a set of data for distributions that are roughly symmetric.
The ______ is a number that measures how far away the typical observation is from the mean.
The standard deviation is a number that measures how far away the typical observation is from the mean. For most distributions, a majority of observations are within one standard deviation of the mean value.
A real estate agent claims that all things being equal, houses with swimming pools tend to sell for less than those without swimming pools. What does this statement mean?
The typical price for homes with pools is smaller than the typical price for homes without pools.