# Math Help - Trend analysis--any advice please on how I should approach this

1. ## Trend analysis--any advice please on how I should approach this

Average number of daily visitors to hotel shown:

Year ======= Quarter ==== Av.No Daily ====== Trend
1 -------------- 1 --------- 90 ------------ 103
-------------- 2 ---------120 ---------- 108
-------------- 3 --------- 200 ---------- 101
-------------- 4 --------- 28 ---------- 85
2 -------------- 1 -------- 22 ----------- 73
-------------- 2 -------- 60 ----------- 67
-------------- 3 -------- 164 ----------- 64
--------------- 4 -------- 16 ------- 65**
3 --------------- 1 -------- 10 --------- 71
--------------- 2 -------- 80 --------- 76
--------------- 3 ------- 192 ----------- 78
--------------- 4 ------- 25 ---------- 82
--
(i) If trend values were calculated using centred four point moving averages, show how value of 65 was calculated

(ii) estimate four quarterly (seasonal) components using ALL the given trend values

(iii) Assuming the trend is broadly linear over the three year period, estimate average number of daily visitors for each quarter of year 4[DO NOT USE REGRESSION ANALYSIS]

Thanks ( sorry for the messy presentation)

Thanks

2. Originally Posted by redskies
(i) If trend values were calculated using centred four point moving averages, show how value of 65 was calculated
Here's some help with the first one,

average(60, 164 ,16, 10) = 62.5

and

average(164,16, 10, 80) = 67.5

The average of those 2 numbers give 65.

What are your ideas for the next parts?

3. Hi, thanks so much for that.I just came across this recently and had no idea about ti.
I don't have access to a textbook on it and the googling was basically unsuccessful.

For (i) , I came across a formula:

$\frac{x_1+2x_2+2x_3+2x_4+x_5}{8}$

Can that be used to show how the value was arrived at also?

(ii) I think this sounds too easy, but should I get average of all Q1 values over given years, then Q2, then Q3?

(ii) I could maybe use the formula that I wrote above and proceed.(but maybe that is taken as regression analysis)

Example, to get average number of visitors for Q1 of year 4

$\frac{10+160+384+50+x_5}{8}=78$

$\frac{604+x_5}{8}=78$

$x_5=10$

therefore....Q1 of Year 4 is 10 ,and so on...

this is probably all wrong.

Thanks for the help.