|
|
Exam-Style Question on Normal DistributionA mathematics exam-style question with a worked solution that can be revealed gradually |
Question id: 80. This question is similar to one that appeared on an IB Standard paper in 2014. The use of a calculator is allowed.
Eels are elongated fish, ranging in length from 5cm to 4m. In a certain lake the length of the eels are normally distributed with a mean of 84cm and a standard deviation of 18cm. Eels are classified as giant eels if they are more than 120 cm long.
An eel is selected at random from the lake.
(a) Find the probability that this eel is a giant.
(b) Given that this eel is a giant, find the probability that it is longer than 130cm.
(c) Two eels are selected at random. Find the probability that they are both giants.
100 eels are selected at random.
(d) Find the expected number of these eels that are giants.
(e) Find the probability that at least 5 of these eels are giants.
|
The worked solutions to these exam-style questions are only available to those who have a Transum Subscription. Subscribers can drag down the panel to reveal the solution line by line. This is a very helpful strategy for the student who does not know how to do the question but given a clue, a peep at the beginnings of a method, they may be able to make progress themselves. This could be a great resource for a teacher using a projector or for a parent helping their child work through the solution to this question. The worked solutions also contain screen shots (where needed) of the step by step calculator procedures. A subscription also opens up the answers to all of the other online exercises, puzzles and lesson starters on Transum Mathematics and provides an ad-free browsing experience. |
|
Drag this panel down to reveal the solution
If you are using a TI-nSpire CX calculator and you would like to see an example of the process used in this question see GDC Essentials. If you would like to interact with the graph of the normal distribution you will find it waiting for you on the Graph Plotter.
The exam-style questions appearing on this site are based on those set in previous examinations (or sample assessment papers for future examinations) by the major examination boards. The wording, diagrams and figures used in these questions have been changed from the originals so that students can have fresh, relevant problem solving practice even if they have previously worked through the related exam paper.
The solutions to the questions on this website are only available to those who have a Transum Subscription.
Exam-Style Questions Main Page
To search the entire Transum website use the search box in the grey area below.
Do you have any comments about these exam-style questions? It is always useful to receive feedback and helps make this free resource even more useful for those learning Mathematics anywhere in the world. Click here to enter your comments.
©1997 - 2024 Transum Mathematics :: For more exam-style questions and worked solutions go to Transum.org/Maths/Exam/
