Variance/Statistical Modeling review

Front

What does the symbol σ represent?

Back

Standard Deviation

Front

What is the formula for calculating the mean (average) of a data set?

Back

μ = (Σx) / n, where Σx is the sum of all data points and n is the number of data points.

Front

Write the equation to model the total cost (y) for buying x packs of pens at $4 each with a $7 shipping fee.

Back

y = 4x + 7

Front

Write the equation to model the total cost (y) for renting a car at Joe's Clown Car Rental Agency, where the base cost is $35 and $0.75 per mile driven.

Back

y = 0.75x + 35

Front

If Ms. Deppe has $150 in her savings account and saves $40 per month, what equation represents her total savings (y) after x months?

Back

y = 40x + 150

Front

What is variance in statistics?

Back

Variance measures the spread of a set of data points around their mean, calculated as the average of the squared differences from the mean.

Front

How do you calculate variance for a sample?

Back

Variance (s²) = Σ(xi - x̄)² / (n - 1), where xi is each data point, x̄ is the sample mean, and n is the number of data points.

Front

What is the difference between population variance and sample variance?

Back

Population variance uses N (total number of data points) in the denominator, while sample variance uses (n - 1) to account for sample size.

Front

What does the term 'outlier' mean in a data set?

Back

An outlier is a data point that is significantly different from other observations, often lying outside the overall pattern of the data.

Front

What is the purpose of using standard deviation in statistics?

Back

Standard deviation quantifies the amount of variation or dispersion in a set of values, indicating how much individual data points differ from the mean.