Edexcel s1 June 2016 unofficial mark scheme

Mean slightly decreases. It adds one to the frequency of the 3-3.5 class and if you actually did the calculation, its shown to decrease. This is because the effect of 3.43 goes onto the midpoint of the class, 3.25 which is less than the mean. Amend

To my understanding, since you actually have a value (3.43), you didn't need to worry about the classes and midpoints. It would be very stupid/sneaky of Edexcel to give you a value which is exactly equal to the mean and then not intend you to use it in the way which you would expect.

It was 2 marks which would suggest some kind of reasoning is needed other than 'oh look it's the same number' and as for using the combining means formula, it said not to do any calculations.

Firsyly, it was 3 marks.

1 mark for saying mean stays the same.
1 mark for saying SD decreases.
1 mark for reasoning for this.

Also, who said you were calculating anything?

On the topic of the mean-
If you put the new value, 3.43, into the table and work out a new mean, the longer way, the mean would decrease. However a better way would be to combine means, which would keep it the same.



I would imagine Edexcel would allow either as you can reason it either way, but this way makes more sense.

I think they'll allow either but staying the same makes more sense to me. Can we stop arguing this, because both might be allowed?

It said with no further calculations

Ok, I managed to get all my answers stored in my calculator at the end, this is what I got. Not 100% sure on all of them, but we can compare.

Question 1Question 2Question 3Question 4Question 5Question 6

Sorry, I didn't have the time to get exact marks. I would imagine 2-3 for each, but I'm not sure.

I reckon 55 for an A

I reckon 55 for an A