358 Continuous data (Chapter 17)a Histogram showing cross-country times b The modal class is 266 t< 31.
c Middle value (x) Frequency (f)
21 : 5 27
24 : 5 51
28 : 5 100
36 75
The mean¼ 29 : 2 mins.EXERCISE 17B
1 Students were asked to draw a sketch of their favourite fruit. The time taken (tmin) was measured for
each student, and the results summarised in the table below.Time (tmin) 06 t< 2 26 t< 4 46 t< 8 86 t< 12
Frequency 10 15 30 60a Construct a histogram to illustrate the data.
b State the modal class.
c Use a graphics calculator to estimate the mean time.2a Represent this data on a histogram.
b Find the modal class.
c3Distance (dm) 206 d< 25 256 d< 35 356 d< 45 456 d< 55 556 d< 85
Frequency 15 30 35 25 15a Draw a histogram of the data.
b What is the modal class?
c4
10 20 30 40 50 60
time ( min)tfrequency densityTravel times to work0Use a graphics calculator to estimate
the mean distance thrown.The histogram shows the times spent travelling to
work by a sample of employees of a large corporation.
Given that people took between and minutes
to get to work, find the sample size used.60 10 20
Use technology to estimate the mean mass.A group of students was asked to throw a baseball as far as they could in a given direction. The results
were recorded and tabled. They were:Mass (mkg) 406 m< 50 506 m< 60 606 m< 65 656 m< 70 706 m< 80
Frequency 25 75 60 70 30When the masses of people in a Singapore fitness club were measured, the results were:0510152020 22 24 26 28 30 32 34 36 38 40
time ( min)tfrequency densitykey represents
10 studentsIGCSE01
cyan magenta yellow black(^05255075950525507595)
100 100
(^05255075950525507595)
100 100
Y:\HAESE\IGCSE01\IG01_17\358IGCSE01_17.CDR Tuesday, 18 November 2008 11:49:41 AM PETER