Chapter 5 Flashcard #1

Front

What is the mean in statistics?

Back

The mean is the average of a set of numbers, calculated by adding all the values together and dividing by the number of values.

Front

What is standard deviation?

Back

Standard deviation is a measure of the amount of variation or dispersion in a set of values. A low standard deviation means that the values tend to be close to the mean, while a high standard deviation means that the values are spread out over a wider range.

Front

What is a z-score?

Back

A z-score indicates how many standard deviations an element is from the mean. It is calculated by subtracting the mean from the value and then dividing by the standard deviation.

Front

What is the total area under the normal curve in a standard normal distribution?

Back

The total area under the normal curve in a standard normal distribution is 1.

Front

What does a z-score of 1.5 indicate?

Back

A z-score of 1.5 indicates that the value is 1.5 standard deviations above the mean.

Front

What is the shape of a normal distribution curve?

Back

The normal distribution curve is bell-shaped.

Front

What is the relationship between the mean, median, and mode in a normal distribution?

Back

In a normal distribution, the mean, median, and mode are approximately equal.

Front

What does it mean if a distribution is asymmetrical?

Back

If a distribution is asymmetrical, it means that the left and right sides of the distribution are not mirror images of each other.

Front

How do you calculate the z-score for a given value?

Back

To calculate the z-score, use the formula: z = (X - μ) / σ, where X is the value, μ is the mean, and σ is the standard deviation.

Front

What proportion of weeks would you expect to have less than 5 accidents if the mean is 6.4 and standard deviation is 1.5?

Back

Approximately 0.1762 or 17.62% of weeks.