Probability & Statistics Semester exam-DEC2022

Front

What is the probability of getting tails on a coin and a 3 on a number cube?

Back

The probability is \( \frac{1}{12} \). This is calculated as \( \frac{1}{2} \) (for tails) multiplied by \( \frac{1}{6} \) (for the number cube showing 3).

Front

What does a box and whisker plot represent?

Back

A box and whisker plot visually displays the distribution of a data set, showing the median, quartiles, and potential outliers.

Front

How do you calculate the probability of an event?

Back

Probability is calculated as \( P(E) = \frac{\text{Number of favorable outcomes}}{\text{Total number of outcomes}} \).

Front

What is the median in a data set?

Back

The median is the middle value when the data set is ordered from least to greatest.

Front

What is the standard deviation?

Back

Standard deviation measures the amount of variation or dispersion in a set of values.

Front

If the mean life of a tire is 30,000 km and the standard deviation is 2,000 km, what is the range for 68% of tires?

Back

The range is from 28,000 km to 32,000 km.

Front

What is a z-score?

Back

A z-score indicates how many standard deviations an element is from the mean. It is calculated as \( z = \frac{(X - \mu)}{\sigma} \).

Front

Calculate the z-score for a value of 265 if the mean is 290 and the standard deviation is 20.

Back

The z-score is \( z = \frac{(265 - 290)}{20} = -1.25 \).

Front

What is the probability of an event that cannot happen?

Back

The probability is 0.

Front

What is the probability of an event that is certain to happen?

Back

The probability is 1.