- This topic has 7 replies, 3 voices, and was last updated 9 years ago by
.
- Posts
Sir, can you help me understand how to calculate this formula?
Y=ax(to the power b)
Lets say a is 45, x is 100 and b = -0.152. How to calculate this mathematically?
how to calculate 100 raised to some negative fraction? Is it something to do with log table? Should we take a log table to the exam hall?You must watch my free lectures on learning curves because I go through how to use the learning curve formula in detail (and I cannot type out the lectures on here 🙂 )
You only need logs in order to calculate b in the formula. It is unlikely that you will need to because b is usually given in the question. However you are not given log tables (and cannot take them with you) – you must have a scientific calculator. That will be capable of calculating logs and also will be capable of calculating 45^(-0.152)
Hello Mr John Moffat
Just to reference the question in BPP kit –Short Scenario MCQ Learning Curve
Crush Co has developed a new product. the first batch of 100 units will take 1500 labour hours to produce. Crush Co has estimated that there will be 85% learning curve that will continue until 6400 units have been produced. Batches after this level will each take the same amount of time as the 64th batch. The batch size will always be 100 units
Note learning index for an 85 % learning curve is -0.2345
Ignore the time value of money.Q-165 –
The total time for the first 16 batches of 100 units was 9000 hours. What was the actual learning rate closest ( to the nearest %)?
A) 80%
B) 75%
C) 78%
D) 73%answer
Batches Total time Average time/unit
1 1500 1500
2 1500*r
4 1500*r>2
8 1500*r>3
16 9000 1500*r>49000=16*1500*r>4
r>4= 9000/(16*1500)
r= 0.78 or 78%The answer is clear however I get different figure in my calculator
Could you kindly explain how did we get r=78% as actual learning rate?
Please don’t type out full questions, because of copyright problems.
In future, just give the number of the question and I will find it 🙂
You say that the answer is clear, which I assume means that you are happy with the line:
r^4= 9000/(16*1500) (r^4 means r to the power 4).So r^4 = 9,000 / 24,000 = 0.375
So r = the fourth root of 0.375.
Different calculators need this inputting in different ways, but the easiest way of getting a fourth root is just to do the square root twice. If you take the square root of 0.375 twice then you get 0.78 (which is 78%)
Thank you Mr John
I cannot thank you enough
I really appreciate your help. It is very kind of you answering all questions for free! Each paper I ask you 1 or 2 questions a paper when I am desperate and as always you solve what exactly I am looking for. I feel shy to ask more questions. Very happy with the answer. It is an issue of using the calculator but I can work the 3rd, fourth and 5th from the first time using shift as you already gave me the clue!
Thank you
- You must be logged in to reply to this topic.