Measures of Center and Standard Deviation

These flashcards cover key concepts regarding measures of center, standard deviation, normal distributions, and data collection methods.

What are the three measures of center in statistics?

Mean, median, and mode.

How do you calculate the mean of a data set?

Sum of all values divided by the number of values.

What is the median of an ordered data set?

The middle value of an ordered data set.

What is the mode of a data set?

The value that appears most frequently in the data set.

What is the formula for standard deviation?

σ = √[(Σ(xi - x̄)²)/n], where xi is each value, x̄ is the mean, and n is the number of values.

What is a normal distribution?

A probability distribution that is bell-shaped and symmetric about the mean.

What percentage of the area under a normal curve lies within 1 standard deviation of the mean?

About 68%.

How do you distinguish between a population and a sample?

A population is the entire group being studied, while a sample is a subset of that population.

What is the difference between a parameter and a statistic?

A parameter is a numerical description of a population characteristic, while a statistic is a numerical description of a sample characteristic.

What type of sampling method gives each member of the population an equal chance of being selected?

Random sampling.