Well-structured Class 11 ISC Maths OP Malhotra Solutions Chapter 31 Moving Average Chapter Test facilitate a deeper understanding of mathematical principles.
S Chand Class 11 ICSE Maths Solutions Chapter 31 Moving Average Chapter Test
Question 1.
The following table gives the recorded monthly sales figures of a certain type of television for the 18-month period commencing 1st January 1989.
Calculate the 6-monthly moving averages and display these and the original figures on the same graph using the same axes for both.
Comment briefly on the purpose of moving average graphs.
Solution:
Calculation of six monthly moving average.
Question 2.
The following table gives the numbers of failures of commercial industries in a country during the years 1975 to 1990 .
Draw a graph illustrating the figures.
Calculate the 4-yearly moving average and plot them on the same graph.
Solution:
Question 3.
The average number, in lakhs, of working days lost in strikes during each year of the period 1981-90 was
| 1981 | 1982 | 1983 | 1984 | 1985 | 1986 | 1987 | 1988 | 1989 | 1990 |
| 1.5 | 1.8 | 1.9 | 2.2 | 2.6 | 2.7 | 2.2 | 6.4 | 3.6 | 5.4 |
Calculate the 3-yearly moving average and draw the moving average graph.
Solution:
| Year | No. of working days lost during strike | 3-yearly moving total | 3-yearly moving average |
| 1981 | 1.5 | ||
| 1982 | 1.8 | 5.2 | 1.73 |
| 1983 | 1.9 | 5.9 | 1.97 |
| 1984 | 2.2 | 6.7 | 2.23 |
| 1985 | 2.6 | 7.5 | 2.5 |
| 1986 | 2.7 | 7.5 | 2.5 |
| 1987 | 2.2 | 11.3 | 3.77 |
| 1988 | 6.4 | 12.2 | 4.07 |
| 1989 | 3.6 | 15.4 | 5.13 |
| 1990 | 5.4 |
Question 4.
The profit of a soft drink firm (in thousands of rupees) during each month of the year is as given below :
| Month | Jan. | Feb. | Mar. | April | May | June | July | Aug. | Sep. | Oct. | Nov. | Dec. |
| Profit (in thousands of rupees) | 3.6 | 4.3 | 4.3 | 3.4 | 4.4 | 5.4 | 3.4 | 2.4 | 3.4 | 1.8 | 0.8 | 1.2 |
Calculate the 4-monthly moving averages and plot these and the original data on a graph sheet.
Solution:
Calculation of 4 yearly moving average
Question 5.
The quarterly profits of a small scale industry (in thousands of rupees) is as follows :
| Year | Quarter 1 | Quarter 2 | Quarter 3 | Quarter 4 |
| 2012 | 39 | 47 | 20 | 56 |
| 2013 | 68 | 59 | 66 | 72 |
| 2014 | 88 | 60 | 60 | 67 |
Calculate 4-quarterly moving averages. Display these and the original figures graphically on the same graph sheet.
Solution:
Question 6.
The number of road accidents in the city due to rash driving over a period of 3 years, is given in the following table :
| Year | Jan. – Mar. | April. – June | July – Sept. | Oct. – Dec. |
| 2010 | 70 | 60 | 45 | 72 |
| 2011 | 79 | 56 | 46 | 84 |
| 2012 | 90 | 64 | 45 | 82 |
Calculate four quarterly moving averages and illustrate them and original figures on one graph using the same axes for both.
Solution:
Calculation of quarterly moving average
