SPM 2020 Add Maths Paper 1, Question 25Probability Distribution
Solved on video in English and Bahasa Melayu · 3 marks · Form 5, Probability Distribution · 5:12 video
The question
Table 3 shows the journey information of train P and train Q. Train P: Town A to Town B, departure 1000, arrival 1358. Train Q: Town B to Town C, departure 1405, arrival 1630. It is given the time travelled, t, in minutes, of train P is normally distributed with mean 238 minutes and variance 4 minutes². On a particular day, Kim took the trains from Town A to Town C through Town B. After arriving in Town B, he needed at least 5 minutes to take train Q. On that day, train P started the journey behind schedule. The probability of train P to reach Town B within the time duration t >= k is 0.2266. Was Kim able to catch train Q? Show your calculation.
[3 marks]
5:12Step 1
t ~ N(238, 2² since variance = 4, so standard deviation = 2.
6 more steps, each with the reason for it, in the full solution
Final answer
Yes: 244.5 < 245 min (k = 239.5)
Where students lose marks
Watch out: finding k = 239.5 is not the end. Turn the timetable into minutes (245) and compare it with 244.5 before answering.
Watch every step of this question solved on video (5:12), with the reason behind each step and a box that checks your own answer.
No card. Every past-year question on video, in English and BM.
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