# Exam failed !

i have done the exam and failed.
I had one questions that was something like that
Y=135+0.78x and said that y was sales volume in thousands and X is the period of quarters.and the based period was q1 2014 and this calculation for 2016
Was like
Q1 13
Q2 14
Q3 15
I don’t remember the exact numbers but was quarterly seasonal variation
Q1 -2000
Q2 +3000
Q3 +4500

I needed to find the trends and the seasonally adjusted sales unit.

I calculate (what was the value on the exam) 135+ 0.78 x 13= 145.14
135+0.78 x 14= 145.92
135 +0.78x15= 146.70
But those are not on thousands and I didn’t understand how to put the sale adjusted volume .
Can anyone explain?

• Hi,

I don't think you're supposed to put exam info on here so your post might get removed, but a couple of things to consider might be:

If Q1 in 2014 is 13, then in 2016 Q1 will be 21, Q2 will be 22 etc so you need to make sure you're using the right 'x' for the year you're doing.

So Q1 in 2016 ----> 135+(0.78x21)=151.38. As Y is in thousands, this would be a sales volume of £151,380.

Then I find it can help if you visualise a graph with 'actual' results and a straight trend line running through it. When the seasonal variation is a positive figure, the actual result is a point above the trend, so actual - seasonal variation = trend. Or Trend + seasonal variation = Actual

I'm pretty sure that in this question the linear equation is your trend line so then you'd just put the numbers in to find your 'actual'.

i.e. 2016 Q1: 151380+(-2000)=149380

That is how I understand it anyway, but please someone correct me if I'm wrong as I did MDCL a while ago!
• Thank you very much, this it’s not the actual exam, it’s what I remember, number are different. But I know what you mean.