Sample stats practice set 1

Front

What is the difference between an experiment and an observational study?

Back

An experiment involves manipulating one variable to determine its effect on another variable, while an observational study involves observing and measuring variables without manipulation.

Front

What is variance in statistics?

Back

Variance is a measure of how much values in a data set differ from the mean of the data set. It quantifies the spread of the data points.

Front

How do you calculate the variance of a data set?

Back

1. Find the mean of the data set. 2. Subtract the mean from each data point and square the result. 3. Find the average of these squared differences.

Front

If a student earns 92% of the points on a 100-point assignment, how many points did they earn?

Back

92 points.

Front

What is the formula for calculating probability?

Back

Probability = (Number of favorable outcomes) / (Total number of outcomes).

Front

How do you find the probability of selecting a rotten apple from a box of apples?

Back

Probability = (Number of rotten apples) / (Total number of apples). In this case, Probability = 50/200 = 0.25.

Front

What is the significance of a control group in an experiment?

Back

A control group is used as a benchmark to compare the effects of the experimental treatment, helping to isolate the effect of the independent variable.

Front

What is the role of randomization in experiments?

Back

Randomization helps eliminate bias by ensuring that each participant has an equal chance of being assigned to any group, which enhances the validity of the results.

Front

What does it mean if a data set has a high variance?

Back

A high variance indicates that the data points are spread out over a wider range of values, showing greater variability.

Front

What is the mean of the data set: 2, 4, 6, 8, 10?

Back

Mean = (2 + 4 + 6 + 8 + 10) / 5 = 6.