W2.1_SSD_Small Size Television Estimated Price


Problem Recognition, Definition and Evaluation
Just quite recently, my wife wanted me to buy a small television. She said that the television should be around 20 – 32 inch, and it should be a flat television.

So, now I need to get my wife a new television. Unfortunately, I am not sure how much the price of a television. So, I went to glodokshop.com to do a bit of research. The goal of research is to find out how much is the price of a small flat panel TV and how much is the reasonable price range for a television with certain characteristics. The data from glodokshop.com is tabulated in Table 1.

Brand Size (inch) resolution (px) power consumption (W) audio output (W) weight (kg) LED/ LCD price (Rp, k)
Polytron 32 1366×768 135 10 12.5 LCD    2,800
Samsung 32 1366×768 155 10 8.66 LCD    2,800
LG 32 1366×768 120 10 9.2 LCD    2,900
LG 32 1366×768 120 10 9.2 LCD    2,900
Samsung 32 1366×768 30 10 8.7 LCD    3,100
Toshiba 32 1366×768 26 20 5 LCD    2,950
Samsung 32 1366×768 70 10 6 LED    3,100
Toshiba 32 1366×768 55 20 5 LED    3,200
Samsung 32 1366×768 70 20 10.9 LCD    3,400
LG 32 1366×768 55 10 6.7 LED    3,251
Samsung 32 1366×768 30 20 5.6 LED    3,324
Samsung 32 1366×768 70 10 7.2 LED    3,800
Sanyo 32 1366×768 100 20 9.8 LCD    4,000
Samsung 32 1366×768 70 20 9 LCD    4,150
LG 32 1366×768 129 20 9.2 LCD    4,200
Samsung 32 1920×1080 40 20 5.6 LED    4,014
Toshiba 32 1920×1080 39 20 9 LED    4,200
Samsung 32 1920×1080 39 20 6.5 LED    4,600
Samsung 32 1920×1080 80 20 10.2 LED    4,500
LG 32 1920×1080 130 20 12 LCD    5,500
LG 22 1366×768 55 200 4.2 LCD    1,575
LG 22 1366×768 27 14 3.6 LED    1,650
LG 22 1366×768 30 14 3.2 LED    1,760
Toshiba 22 1920×1080 40 20 4.4 LED    1,850
Samsung 22 1920×1080 22.4 6 3.5 LED    1,975
Polytron 24 1920×1080 30 10 4.8 LED    1,950
Toshiba 22 1920×1080 40 20 4.4 LED    2,000
Sanyo 24 1366×768 57 6 5.5 LCD    1,750
Toshiba 24 1366×768 65 20 8.5 LCD    1,900
Toshiba 24 1920×1080 40 20 5.5 LED    2,300
LG 32 1366×768 55 24 6.7 LED    3,220

Table 1. List of small size television price (Retrieved from www.glodokshop.com)

Development of Feasible Alternatives
Based on the information in Table 1, I need to find a formula which I can use to predict the TV price based on its screen size, panel type, panel resolution, weight, power consumption and audio output.

I replaced each non numeric parameter with a numeric value. The mapping is shown in Table 2.

Brand resolution (px) LED/LCD
LG 2 1366×768 2 LCD 2
Polytron 3 1920×1080 3 LED 3
Samsung 5
Sanyo 7
Toshiba 11

Table 2. Mapping of non-numeric parameter with numeric value

The result of the mapping is shown in Table 3.

Brand Size (inch) resolution (px) power consumption (W) audio output (W) weight (kg) LED/ LCD price (Rp, k)
5 32 2 135 10 12.5 2   2,800
6 32 2 155 10 8.66 2   2,800
3 32 2 120 10 9.2 2   2,900
3 32 2 120 10 9.2 2   2,900
6 32 2 30 10 8.7 2   3,100
10 32 2 26 20 5 2   2,950
6 32 2 70 10 6 3   3,100
10 32 2 55 20 5 3   3,200
6 32 2 70 20 10.9 2   3,400
3 32 2 55 10 6.7 3   3,251
6 32 2 30 20 5.6 3   3,324
6 32 2 70 10 7.2 3   3,800
7 32 2 100 20 9.8 2   4,000
6 32 2 70 20 9 2   4,150
3 32 2 129 20 9.2 2   4,200
6 32 3 40 20 5.6 3   4,014
10 32 3 39 20 9 3   4,200
6 32 3 39 20 6.5 3   4,600
6 32 3 80 20 10.2 3   4,500
3 32 3 130 20 12 2   5,500
3 22 2 55 200 4.2 2   1,575
3 22 2 27 14 3.6 3   1,650
3 22 2 30 14 3.2 3   1,760
10 22 3 40 20 4.4 3   1,850
6 22 3 22.4 6 3.5 3   1,975
5 24 3 30 10 4.8 3   1,950
10 22 3 40 20 4.4 3   2,000
7 24 2 57 6 5.5 2   1,750
10 24 2 65 20 8.5 2   1,900
10 24 3 40 20 5.5 3   2,300
3 32 2 55 24 6.7 3   3,220

Table 3. Mapping of Table 1 and Table 2

On the data in Table 3, a regression analysis was performed, for both linear and logarithmic analysis, to get the best fit formula. The linier regression would produce the following formula:

Price = A x type + B x weight + C x audio + D x wattage + E x resolution + F x size + G x brand + H

The logarithmic regression would produce the following formula:

ln(Price) = (type x ln(A)) + (weight x ln(B)) + (audio x ln(C)) + (wattage x ln(D)) + (resolution x ln(E)) + (size x ln(F))+ (brand x ln(G))+ ln(H)

Development of outcomes for each alternative
The linear regression analysis was carried out using MS Excel, and the result is shown at Table 4.

G F E D C B A H
47.660 85.838 2.521 -2.111 869.044 190.139 -25.417 -4995.290

Table 4. Linear regression result on the data from Table 3

So, the linear regression formula is:

Price = (-25.417 x brand) + (190.139 x size) + (869.044 x resolution) + (-2.111 x wattage) + (2.521 x audio) + (85.838 x weight) + (47.660 x panel type) – 4995.290

The logarithmic regression analysis was carried out using MS Excel, and the result is shown at Table 5.

G F E D C B A H
1.035223 1.023973 1.00044392 0.99939 1.265946 1.0735 0.996411 172.7626

Table 5. Logarithmic regression result on the data from Table 3

So, the linear regression formula is:

ln(Price) = (brand x ln(0.996411)) + (size x ln(1.0735)) + (resolution x ln(1.265946)) + (wattage x ln(0.99939)) + (audio x ln(1.00044392)) + (weight x ln(1.023973))+ (panel type x ln(1.035223))+ ln(172.7626)

Selection of Criterion
The R2 value represents the coefficient of determination, which indicates how well the estimated Y (PRICE) compares to the actual Y (PRICE). The estimated Y is produced from the calculation, where the actual Y is from actual data. The value of R2 is between 0 and 1. In a perfectly fit situation, the estimated Y is equal to actual Y, making R2 equal to 1. The closer R2 to 1, the better the formula predicts the actual Y value.

Analysis and Comparison of the Alternatives
Based on the calculation, the R2 value for each option is as follow:

  1. Price = (-25.417 x brand) + (190.139 x size) + (869.044 x resolution) + (-2.111 x wattage) + (2.521 x audio) + (85.838 x weight) + (47.660 x panel type) – 4995.290;
    R2= 0.827600612
  1. ln(Price) = (brand x ln(0.996411)) + (size x ln(1.0735)) + (resolution x ln(1.265946)) + (wattage x ln(0.99939)) + (audio x ln(1.00044392)) + (weight x ln(1.023973))+ (panel type x ln(1.035223))+ ln(172.7626);
    R2= 0.895936057

Selection of Preferred Alternatives
As per the information above, the closer the R2 value to 1 is the second formula which is:

ln(Price) = (brand x ln(0.996411)) + (size x ln(1.0735)) + (resolution x ln(1.265946)) + (wattage x ln(0.99939)) + (audio x ln(1.00044392)) + (weight x ln(1.023973))+ (panel type x ln(1.035223))+ ln(172.7626)

Using the formula, the price for a certain type of television can be determined.

If I want to purchase a 32inch Toshiba with full HD resolution (1920×1080), wattage 50watt, with 20watt audio output, weight 10kg and LED panel, the price would be Rp5,691,000.

For a television with similar specification, but having Samsung brand, the price will be Rp 5,815,000.

Applying the formula and its standard deviation to the raw data, will provide information on which television is sold at cheap price, reasonable price and expensive price.

Table 6 shows the result.

Brand Size (in) res. (px) power (W) audio (W) weight (kg) LED/ LCD price (Rp, k) Est. Price (Rp,k) Min Price (-1σ) Max Price (+1σ) Cheap?
Polytron 32 1366×768 135 10 12.5 LCD 2,800 3,538 3,111 4,024 cheap
Samsung 32 1366×768 155 10 8.66 LCD 2,800 3,169 2,786 3,604 in the range
LG 32 1366×768 120 10 9.2 LCD 2,900 3,314 2,913 3,769 cheap
LG 32 1366×768 120 10 9.2 LCD 2,900 3,314 2,913 3,769 cheap
Samsung 32 1366×768 30 10 8.7 LCD 3,100 3,421 3,008 3,891 in the range
Toshiba 32 1366×768 26 20 5 LCD 2,950 3,088 2,715 3,512 in the range
Samsung 32 1366×768 70 10 6 LED 3,100 3,243 2,851 3,688 in the range
Toshiba 32 1366×768 55 20 5 LED 3,200 3,141 2,762 3,573 in the range
Samsung 32 1366×768 70 20 10.9 LCD 3,400 3,533 3,107 4,019 in the range
LG 32 1366×768 55 10 6.7 LED 3,251 3,363 2,957 3,825 in the range
Samsung 32 1366×768 30 20 5.6 LED 3,324 3,305 2,906 3,759 in the range
Samsung 32 1366×768 70 10 7.2 LED 3,800 3,336 2,933 3,794 expensive
Sanyo 32 1366×768 100 20 9.8 LCD 4,000 3,356 2,951 3,817 expensive
Samsung 32 1366×768 70 20 9 LCD 4,150 3,378 2,970 3,842 expensive
LG 32 1366×768 129 20 9.2 LCD 4,200 3,310 2,911 3,765 expensive
Samsung 32 1920×1080 40 20 5.6 LED 4,014 4,159 3,657 4,730 in the range
Toshiba 32 1920×1080 39 20 9 led 4,200 4,414 3,881 5,021 in the range
Samsung 32 1920×1080 39 20 6.5 LED 4,600 4,251 3,738 4,835 in the range
Samsung 32 1920×1080 80 20 10.2 LED 4,500 4,527 3,980 5,149 in the range
LG 32 1920×1080 130 20 12 LCD 5,500 4,475 3,935 5,090 expensive
LG 22 1366×768 55 200 4.2 LCD 1,575 1,638 1,441 1,864 in the range
LG 22 1366×768 27 14 3.6 LED 1,650 1,566 1,377 1,781 in the range
LG 22 1366×768 30 14 3.2 LED 1,760 1,548 1,361 1,761 in the range
Toshiba 22 1920×1080 40 20 4.4 LED 1,850 1,946 1,711 2,213 in the range
Samsung 22 1920×1080 22.4 6 3.5 LED 1,975 1,955 1,719 2,224 in the range
Polytron 24 1920×1080 30 10 4.8 LED 1,950 2,334 2,052 2,654 cheap
Toshiba 22 1920×1080 40 20 4.4 LED 2,000 1,946 1,711 2,213 in the range
Sanyo 24 1366×768 57 6 5.5 LCD 1,750 1,753 1,541 1,994 in the range
Toshiba 24 1366×768 65 20 8.5 LCD 1,900 1,858 1,633 2,113 in the range
Toshiba 24 1920×1080 40 20 5.5 LED 2,300 2,302 2,024 2,618 in the range
LG 32 1366×768 55 24 6.7 LED 3,220 3,384 2,975 3,849 in the range

Table 6. Application of the formula to identify which televisions is in reasonable price, cheap and expensive.

Based on Table 6, a Polytron, 24 inch with Full HD, 30watt power consumption, 4.8kg of weight, and LED panel is consider cheap if it is sold with a price of Rp 1,950k.

Performance monitoring and post evaluation result
The formula should be good enough for the time being, as the data is limited. But, to make better formula, this formula should always be tested against actual cost from time to time. If the actual seems to be significantly different from the estimated value, the formula should be reviewed.

References
Dysert, L. R. (2012). Estimating. In S. Amos (Ed.), Skill & Knowledge of Cost Engineering (5th Ed.) (pp.9.1-9.34). USA: CreateSpace.

Television data and prices. (September 14, 2013). Retrieved from glodokshop.com

Toshiba television detail specifications. (September 14, 2013). Retrieved from toshiba.com

Samsung television detail specifications. (September 14, 2013). Retrieved from samsung.com

LG television detail specifications. (September 14, 2013). Retrieved from LG.com

Sanyo television detail specifications. (September 14, 2013). Retrieved from http://www.haier.com/ph/sanyoproduct/tv/

Sullivan, W. G., Wicks, E. M., & Koelling, C. P. (2012). Engineering Economy (15th Ed.) (pp. 67-94). New Jersey, United States: Prentice Hall.

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1 Comment

Filed under Sadat SD, Week 02

One response to “W2.1_SSD_Small Size Television Estimated Price

  1. AWESOME reposting, Pak Sadat!!!! Nice work!!! Now you are demonstrating that you know how to use these tools/techniques to help you make better decisions.

    Keep up the good work and looking forward to seeing more postings like this in the future!!

    BR,
    Dr. PDG, Jakarta

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