InterviewSolution
Saved Bookmarks
InterviewSolution
| 1. |
Electric buses are becoming popular nowadays. These buses have the electricity stored in a battery. Electric buses have a range of approximately 280 km with just one charge. These buses are superior to diesel buses as they reduce brake wear and also reduce pollution. Transport department of a city wants to buy some electric buses for the city. So, the department wants to know the distance travelled by existing public transport buses in a day.The following data shows the distance travelled by 50 existing public transport buses in a day.Daily distance travelled (in km)100 - 120120 - 140140 - 160160 - 180 180 - 200Number of buses12148610(a) Find the 'median' distance travelled by a bus.(b) Find the 'mean(average)' distance travelled by a bus. |
|||||||||||||||||||||||||||||||||||
Answer»
(a) \(\because N = \sum f_i = 50\) \(\frac N 2 = 25\) Cumulative frequency which is just greater than 25 is 26. \(\therefore\) 120 - 140 is median class \(\therefore\) l = 120 cf = 12 f = 14 h = 20 \(\therefore\) Median = \(l + \cfrac{\frac N2-cf}{f}\times h\) \(=120 + \frac{25 - 12}{14}\times 20\) \(=120 + \frac{13}{14}\times 20\) = 120 + 18.57 = 138.57 \(\therefore\) Median distance travelled by bus = 138.57 Km (b) Mean = \(\frac{\sum f_Ix_i}{\sum x_i}\) \(= \frac{7260}{50}\) \(= \frac{726}{5}\) = 145.2 \(\therefore\) Mean distance travelled by bus = 145.2 Km |
||||||||||||||||||||||||||||||||||||