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### History and Feedback

#### Checkpoint description

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#### Christian Lawson-Perfect2 years, 1 month ago

Gave some feedback: Ready to use

#### Christian Lawson-Perfect2 years, 1 month ago

Saved a checkpoint:

This is a good question.

I've changed the titles of the films to randomly-generated ones because (a) they were a bit stereotypically boy-heavy and (b) they'll really date this question. There's also (c) are we allowed to use trademarks?

Published this.

#### Elliott Fletcher2 years, 2 months ago

I have inverted the table and moved it into the statement and i have also added an extra part about Genre.

#### Elliott Fletcher2 years, 2 months ago

Gave some feedback: Needs to be tested

#### Chris Graham2 years, 2 months ago

Gave some feedback: Has some problems

#### Chris Graham2 years, 2 months ago

Can we invert the table so that "Film" and "P(Film)" are columns? Also, the table and everything above it should be the question's statement, with the part beginning "100 people..."

It's a nice straight-forward question, but you could add a little bit to this with an extra column "Genre", ie. action, comedy, sci fi etc. And then ask the student to calculate the expected number going to see a particular genre (of which there is say 2 films). Just make sure that you still have 'nice' numbers if you do this, so that the expected value comes to a whole number.

#### Lauren Richards2 years, 2 months ago

• I think the question statement should just be right at the start of the advice.
• I actually think the two parts should be completely separate questions. There are definitely enough individual questions in part b) to make it a good lengthy question with i), ii) and iii) as individual parts that can be marked separately. You can relatively easily add in another question part for part a) to lengthen it if you wanted to. Maybe something about age ratings or something.
• b)ii) I would programme in a fraction with gap fills so they can answer it like that rather than getting them to do a fraction with no fraction sign and no instruction to do it like a/b.
• I think this is a great question, and I can't find very much wrong with it at all, well done Elliott!

#### Elliott Fletcher2 years, 2 months ago

Gave some feedback: Needs to be tested

#### Hannah Aldous2 years, 2 months ago

just a few things to comment on

• in the statement equation it says 'expected of times' which doesn't make sense
• maybe you could explain what p(film) is somewhere
• the way you have phrased '120 people buy tickets to see one of...' makes it sound like they all bought the same film ticket
• i think you can omit 'by rolling a 2 or 4' in b i as you say it twice
• in your advice for b ii you could maybe state the frequncy of outcome a bit clearer and after the equation
• maybe in your advice you could adapt it when the fraction can't be simplified to simply say it is in it's simplest form
• in advice for the last part you can omit 'using the experimental data' as you say it twice

#### Hannah Aldous2 years, 2 months ago

Gave some feedback: Has some problems

#### Elliott Fletcher2 years, 2 months ago

Gave some feedback: Needs to be tested

#### Elliott Fletcher2 years, 2 months ago

Created this.
Calculating Expected Values given a table of probabilities Ready to use Elliott Fletcher 01/08/2017 12:12
Calculating expected values given a table of probabilities Needs to be tested Lauren Frances Desoysa 21/08/2018 15:22
NumericalReasoning15 draft Raymond Corrigan 16/09/2018 00:50
NumericalReasoning16 draft Raymond Corrigan 18/09/2018 12:05
NumericalReasoning17 draft Raymond Corrigan 18/09/2018 12:13
Michael's copy of Calculating Expected Values given a table of probabilities draft Michael Proudman 19/11/2018 12:02
Calculating expected values given a table of probabilities draft Ryan Poling 27/01/2019 16:37
Simon's copy of Calculating Expected Values given a table of probabilities draft Simon Thomas 13/05/2019 09:55

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