Mathematics 2 ESO – Unit 12 STATISTICS page 125 activity 45
a) Make a “frequency table”:
- I) We ask 15 people how many books they read last year. The result is: 2, 0, 1, 4, 0, 2, 0, 3, 1, 0, 2, 3, 1, 2, 1
- II) We ask 16 bus passengers how happy they are about the bus service. The result is: good, bad, very good, very bad, good, bad, good, good, good, bad, very good, bad, good, bad, very good, good.
b) Relate each type of chart with a description:
| Bar charts a) | 1. The angle for each category = value of the category • 360° / total value of all the categories. |
| Pie charts b) | 2. These charts show discrete (discontinuous) data. |
| Histograms c) | 3. These charts show continuous data. |
c) We ask 20 people how many friends they have, their answers are: 3, 2, 6, 4, 8, 2, 12, 5, 0, 1, 6, 2, 4, 3, 5, 1, 4, 3, 5, 4
- I) What graph is correct, a bar chart or a histogram? Why?
- II) Draw the graph.
- III) Draw also a pie chart
d) The graph shows the number of fans of a music band in six countries.
- I) What type of graph is it?
- II) Make a frequency table.
- III) Calculate: the mean, the mode, the median, the relative frequency, the absolute frequency, the cumulative frequency
- IV) Calculate the angle for each category in a pie chart.
- V) Draw a pie chart.
e) Ninety six people like icecream, eight people don’t like icecream.
- I) Calculate the angle for each category in a pie chart.
- II) Draw a pie chart.
f) The number of people waiting at the bus stops along a bus line is: 2, 0, 1, 1, 3, 2, 5, 2, 1, 2, 1, 4, 1, 2, 0, 1, 2, 3, 0, 2, 1, 3, 0, 1, 3
- I) What is the population?
- II) What is the absolute frequency of stops with 2 people waiting?
- III) Calculate the the absolute frequency of stops with 2 people waiting?
- IV) Draw a bar chart.
- V) Draw a frequency polygon.
- VI) Calculate the mean, the mode and the median.
g) In a city of 4 million inhabitants we ask eighty people how many times they go to the swimming pool during the first week of July.
| Number of people | Number of times they go to the pool |
| 12 | 0 |
| 16 | 1 |
| 25 | 2 |
| 12 | 3 |
| 8 | 4 |
| 4 | 5 |
| 2 | 6 |
| 1 | 7 |
- I) What is the population?
- II) What is the sample?
- III) How many categories are there? Which are the categories?
- IV) Which is the absolute frequency of people that goes two times to the pool?
- V) What is the relative frequency of people that goes four times to the pool?
- VI) Draw an appropriate chart.
- VII) Calculate mean, mode and median.
h) True or false?
- I) The population is always smaller than the sample.
- II) In a statistic there are always seven categories.
- III) Frequency is how often something happens
- IV) The median is the number in the middle of a group.