Normal Distribution Bell Curve and 2 way table Flashcard

Front

What is a normal distribution?

Back

A normal distribution is a probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean.

Front

What does the bell curve represent?

Back

The bell curve represents the normal distribution, where most of the observations cluster around the central peak and probabilities for values further away from the mean taper off equally in both directions.

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 does it mean if a score is 2.5 standard deviations above the mean?

Back

It means the score is significantly higher than the average score, indicating better performance compared to the majority of the data.

Front

What percentage of data falls within one standard deviation of the mean in a normal distribution?

Back

Approximately 68% of the data falls within one standard deviation of the mean.

Front

What percentage of data falls within two standard deviations of the mean in a normal distribution?

Back

Approximately 95% of the data falls within two standard deviations of the mean.

Front

What percentage of data falls within three standard deviations of the mean in a normal distribution?

Back

Approximately 99.7% of the data falls within three standard deviations of the mean.

Front

What does the symbol 'σ' represent?

Back

The symbol 'σ' represents standard deviation in statistics.

Front

What is the area under the normal distribution curve?

Back

The total area under the normal distribution curve is equal to 1 (or 100%).

Front

What does it mean if a data point lies outside of ±3 standard deviations?

Back

It indicates that the data point is an outlier, as it falls outside the range where 99.7% of the data is expected to lie.