Continuous Data Calculating Averages with

A group of 50 nurses were asked to estimate a minute. The results are shown in the table. Time (seconds)Frequency 10 < t ≤ < t ≤ < t ≤ < t ≤ < t ≤ < t ≤ < t ≤ < t ≤ < t ≤ 1002 Example 1

Estimating a minute - nurses results Time (seconds) FrequencyFrequency

Time (seconds)Frequency 10 < t ≤ < t ≤ < t ≤ < t ≤ < t ≤ < t ≤ < t ≤ < t ≤ < t ≤ 1002 Use the end points of each class interval for the scale on the horizontal axis

Time (seconds) FrequencyFrequency Estimating a minute - nurses results

Averages Mode – with grouped data this is called the modal group or class. Modal group 60 < t ≤ 70 Time (seconds)Frequency 10 < t ≤ < t ≤ < t ≤ < t ≤ < t ≤ < t ≤ < t ≤ < t ≤ < t ≤ 1002

Estimated mean grouped data so the mean is estimated. Time (seconds) Frequency 10 < t ≤ < t ≤ < t ≤ < t ≤ < t ≤ < t ≤ < t ≤ < t ≤ < t ≤ 1002 Mid- point Estimated mean = sum of mid-point x freq = total frequencies = 2930 = 58.6 seconds 50 Mid-point x Frequency Total

1: Find the modal group, median and estimate the mean from the table below. 2: Draw a histogram to represent the data. Michelle keeps a record of the number of minutes her train is late each day. The table shows her results for a period of 50 days.

Time (seconds)Frequency 10 < t ≤ < t ≤ < t ≤ < t ≤ < t ≤ < t ≤ < t ≤ < t ≤ < t ≤ 100