a) The following data show the cost of electricity (in RM) during a summer month for a random sample of 50 one-bedroom apartments in a large city.
88, 92, 97, 102, 104, 108, 110, 117, 117, 118
119, 125, 126, 127, 129, 131, 133, 136, 137, 138
141, 145, 146, 149, 150, 150, 152, 154, 154, 154
155, 155, 157, 162, 162, 165, 166, 167, 168, 169
172, 175, 175, 184, 189, 189, 195, 196, 208, 210
i. Construct a frequency distribution.
ii. Using the result from part (i), calculate the relative frequencies for each class.
iii. Using the result from part (i), calculate the cumulative frequencies for each class.
iv. Construct a frequency histogram for these data.
v. Using the result from part (i), compute the mean.
vi. Using the result from part (v), compute the standard deviation.
b) The data below shows a stem-and-leaf plot.
1 | 4 5
2 | 1 1 1 2 3 4
2 | 7 7 7 8 8 9 9 9 9 9
3 | 0 1 1 2 3 4 4 5
3 | 6 6 6 7 8 8 9
4 | 0 0
i. Calculate the range for the above data.
ii. Find the median and mode for the above data.
iii. Which class show the highest frequency.