Data collection, sampling, averages and spread

By the end you’ll be able to

• Classify data as qualitative, discrete or continuous, understand populations and random samples, and identify sources of bias and ways to reduce it
• Calculate mean, median, mode and range from lists and frequency tables, and estimate the mean of grouped data using midpoints
• Identify the modal class and the class containing the median of grouped data, and explain why a grouped mean is only an estimate