6-3 Statistics Practice Quiz

In a bar graph, each bar represents the frequency of a particular category. The height of the bar shows how many times that category occurs.

The mean is calculated by adding the numbers and then dividing by the count. Here, (4+6+8)/3 equals 6.

The mode is the most frequently occurring value in a dataset. It is different from the mean and median, which represent the average and middle value respectively.

The median is the central number in an ordered list of values. It divides the dataset into two equal parts and is less sensitive to outliers.

Each slice of a pie chart reflects the proportion of the whole corresponding to a category. It visually represents how that category compares to the total.

A scatter plot displays individual data points on a coordinate plane, highlighting potential relationships. It is specifically designed to show correlations between two quantitative variables.

The range is calculated by subtracting the smallest value from the largest value in the set. For this dataset, 20 - 3 equals 17.

Surveying only one class may not capture the views of the entire school. This results in sample bias, where the sample does not represent the broader population.

The median, being the middle value, is less affected by very high or very low numbers. It can provide a better central measure when outliers are present.

Line graphs are primarily used to display changes or trends over a continuous period. They help visualize how data evolves over time.

To find the mean, add all values (10+20+15+25+30 = 100) and divide by the number of values (5). Thus, the mean is 100/5, which equals 20.

An outlier is a data point that stands out due to its deviation from other values. It can indicate variability or potential errors in data collection.

A histogram groups continuous data into intervals or bins. It is effective for visualizing the frequency distribution of continuous variables.

In skewed distributions, extreme values can bias the mean. The median provides a more accurate measure of the central tendency when outliers are present.

Data points rising from left to right indicate a positive correlation, meaning higher values of one variable are associated with higher values of the other. This demonstrates a consistent increasing trend between the variables.

The line drawn inside the box in a box-and-whisker plot indicates the median of the dataset. This line splits the data into two halves, providing a clear central value.

Standard deviation measures the average distance of data points from the mean. It quantifies the spread or dispersion in a dataset, making it especially valuable for understanding variability.

The weighted mean assigns weights to each group based on its size, ensuring that larger groups influence the average more than smaller ones. This leads to a fair comparison between groups of different sizes.

Simpson's Paradox occurs when trends observed in individual groups reverse when the groups are combined. It highlights the importance of analyzing subgroups separately to understand the true relationships in data.

A Q-Q plot (quantile-quantile plot) compares the quantiles of the data with the expected quantiles of a normal distribution. It is a powerful visual tool for assessing normality in a dataset.