I know you made this video 9 years ago, but I just want you to know that you're still helping students till' this day. Your explanation is very clear and I have finally grasped this topic after many trials and errors. Thank you so much

Oh Ok, well that's a relief. Thanks for the reply. It's good to know that lots of students are finding it helpful!

12 years kater and it still helps me a lot!! Thank you so much

Incredibly helpful and well explained; you did a much better job than our MBA prof. Pleasant voice to listen to without any distractors. Thanks again!

That's the spirit!! It might sound odd, but a positive attitude helps so much. Good luck with your exam!

This scored me a lot of marks for my exam, Thank you very much❤

Finally a proper video! Thank you so much!

You explained it so simply, thank you

Ur a genius thank u so much, god bless

Thanks so much. This was very helpful and easy to understand before the day of my test!

I ran a least squares regression using a calculator. You go into the stat lists of your calculator and put in the coordinates (1, 71) (2, 71) (3, 71) (4, 63) (5,73) & so on for all the data points. Then depending on your calculator the next step is different. You go into the stat menu and get a Linear regression. It probably looks like LinReg(a+bx) or something like that. It'll give you an equation based on those data points. What model of calculator do you have? I could google the steps for you

Presentation is clear and easy to follow well done

you are a genious hey.. God bless you so much, noone does it better than you

youre better than my teacher! i feel im going to ace my Exams this year

@supershrimp1 You're most welcome. Good luck for the exams. Nearly at the finish line!! :-)

LIFE SAVER. My gratitude to you.

Thank you very much! great work! Will help my for my exam soon. Thanks

thank u so much ... it really helps me a lot .. praying for you

You count up each data point you have, sequentially. I explain it later in the video in relation to question 13 from the exam. But basically Q1 2003 is your first data point so you can that x=1. Q2 2003 is second so that's x=2. Q3 2003; x=3. Q4 2003; x=4. Q1 2004; x=5. Q2 2004; x=6. Q3 2004; x=7. Q4 2004; x=8. Q1 2005; x=9. Q2 2005; x=10. Q3 2005; x=11. Q4 2005; x=12. and then we get to... Q1 2005; x=13.

I cannot believe I only just discovered these!.... an hour before my exam!

Thank you. I found this to be very helpful

Thank you for this, i want to know based on you chosen 1 then 2 then 3.... for the regression line equation is it based on the sequence of periods ? if that yes,, how we can know the actual sales when we go from quarter to monthly ? " what i mean the level of period details " for example, you calculated 77.82 for 2006 Q1 , what the the sales for Jan?Feb?Mar? in this quarter ?

How did you get y= 0.78x + 67.68???

Teşekkürler from Turkey! Veeery helpful for university midterm!

Wow! How i wish you were my further maths teacher! Great help :)

There are 4 quarters. Step 1: Center the means - Q3/2003: 68.875, Q4/2003: 69.50, Q1/2004: 69.875, Q2/2004: 71.75, Q3/2004: 73.625, Q4/2004: 74, Q1/2005: 74.625, Q2/2005: 75.75 Step 2: the proportion Quarterly Sales/Centered Mean.- Q3/2003: 0.914700544, Q4/2003: 1.079136691, Q1/2004: 1.073345259, Q2/2004: 0.919860627, Q3/2004: 0.869269949, Q4/2004: 1.202702703, Q1/2005: 1.018425461, Q2/2005: 0.897689769 Step 3: Work out the unadjusted seasonal index Q1: 89.20%, Q2: 114.09%, Q3, 104.59%, Q4: 90.88% Step 4: The average of the above unadjusted seasonal index: 99.69%, which should be adjusted to 100%. → The adjusted ratio is 1/99.69%=100.312% Step 5: Seasonal index: Q1: 89.20%*100.312%=89.48%, Q2:114.45%, Q3: 104.61%, Q4: 91.16%

Omg so much easier than what I thought it would be. Lol mast minute study before my exam that's in 2 hours -_-

Helpful video, but I think when finding the equation of the least squares trend line for the deseasonalised data you entered the wrong formula of Y=a•x+b. I entered a+b•x and got a different answer.

If a company only has past data for 1 year, how should it go about forecasting for future months mitigating the seasonal effects?

If i pass core tomorrow, its thanks to you !

G R A C I A S mil desde COLOMBIA. It works perfectly with animal production. I do something similar using percentage. Thanks in advance!!!

Excellent video, really helped. Thanks

i enjoy your method of teaching thnx mam

How would you calculate the seasonal indices if you had an incomplete data set for 2005. Say you have all of the data from Q1-4 for 2003 and 2004 but only Q1 and Q2 for 2005? Would you only use 2003 and 2004 to calculate the seasonal indices?

Hi. Thank you for this. This is very informative. Can i use this method to forecast daily sales?

Thank you very much ,GOD bless you

Can you do a video doing seasonality based on CMA? Thank you

Thank you, am from Kenya

I have 15 years radiosond temperature data. How can I calculate annual oscillation, semiannual oscillation and triannual oscillation?

thank you very much , my gratitude and God bless you

A wonderful video!

Great piece of work.

Thank you so much for this video!

@mothertyler haha nah its thanks to your hard work and studying up. Good luck in the morning!! :-)

Hi! can we find the seasonal indices for data that only have 1-year of actual sales data?

Great tutorial, how would you deseasonalise that data??????

can soemone pls tell if we have predict for three more year which is 2006 2007 2008 how will we do that

15:40 I found the sheet I'm working on

Thank you very much, God bless you :)

Hi, I have a 12 month data . Demand for sure is seasonal. But the sum of seasonal index is not coming out to be one as at some places net demand is negative or zero. In that case, will my seasonality calculation hold right?

Really helpful & meaningful vdo👍

I don't know what depersonalise is, sorry! Do you mean deseasonalise? Not sure I can help you :(

What annotation tool are you using to draw on screen?

Can you tell me how you got your y value of 0.78x and where did you get 67.68 from?

Thank you so much!

Hi, I need to depersonalised my daily bus ridership data but I need to remove the effect of two periods. they are month of year and day of week both. how do I depersonalised them. should I depersonalised day of week first and then take that depersonalised data to depersonalised the month of the year. please let me know. thank you

Great video

THANKYOU U MAKE CRAMMING WORK

Could someone help me figure this out, thanks! *Question 12* *The seasonal index for heaters in winter is 1.25.* *To correct for seasonality, the actual heater sales in winter should be* A. reduced by 20%. B. increased by 20%. C. reduced by 25%. D. increased by 25%. E. reduced by 75%. _This has been take from VCAA Further maths exam 2014_ I know for a fact that this is how you solve it : _1/1.25= 0.8_ and the answer therefore is A; but *where did the "1" come from?*

Parts of the tutorial: 6:56 Deaseasonalising 9:02 Deasonalised Graph 15:52 Exam Questions

Thank you so much for this video....!!! :)

can we use this same for cyclical monthly data

It's just so people can easily navigate to parts of the video which interest them :)

Why not test the data from forecast eror with MAD or TS ? How we know that forecast is well, Not wrong

where did you get x=13 from? for Q1 2006?

yooooooooooooooo yung rupe what's good brah?

it seems like i will finish my degree on record time i really dealived by this chapter

that's so helpful

Thank u soooooooo much

Can you please calculate the SI of 2006

you are the best :)

Where did you get the numbers 0.78 and 67.68?

Anybody knows why she isn’t making new vids?

Not sure what you mean... have I made a mistake at those points? Have a spelled something wrong? Eeek! I've watched those bits and I can't figure out what you're referring to, sorry! Are you just highlighting the useful parts so people can skip past all my waffle?? Hehe. That would be useful, I'm guessing :)

Excelent!

your the bomb

"The Hale Way"

Haha, you kept spelling deseasonalised wrong. Thanks for the video though :p

U r so fucking amazing

Tdaa

I don't know why you didn't just average the sales for each quarter first.

fanx a lot but your tone is like eish

waw

Are you Australian?

Thanx, but plz try not to shout when you say ACTUAL!

pretty please

Ur a genius thank u so much, god bless

Thank you so much!