Answer to Question #277358 in Statistics and Probability for April

Question

1.    Observations from the first 25 days of the year showed that the following number of pedestrians used a particular crosswalk on each day:

19 132 25 78 62 101 84 32 99 71 43 56 64 81 59 67 43 97 105 91 31 66 76 87 125

(8 marks)

a.    Construct a frequency distribution for this data using a lower limit for the first class of 15 and a class width of 20. Indicate the class limits, boundaries, midpoints, frequencies and cumulative frequencies.

Answer 1

The frequency distribution is given by below table,

The classes of the type 15-34, 35-54, etc. in which both upper and lower limits are included are called inclusive classes.

Above table that showing the distribution of frequencies in different classes is called a frequency table.

Midpoint = (Lower class limit + Upper class limit) / 2  

The frequencies and cumulative frequencies are shown in the above table.