We’ve been asked on our Facebook wall.
We’ve been repeatedly asked on this blog’s comments sections.
Errr … we’ve even been pui-ed for this 🙁
Lest you feel forgotten, abandoned or unloved, let me assure the H1SD Maths Generation that you were never far from my mind while I toiled through the H2 solutions as well as my tuition classes in the past days.
Ok 废话少说, here’s the stuff you’ve been waiting for.
Click the 
button and grab it here!
Latest version:
- 1.1:
Q9(ii) – added “the advertised price decreases as the car’s age increases in a linear fashion” in response to this.
Q11(ii) – corrected the typo “insufficient evidence” to “sufficient evidence” in the concluding statement of the hypothesis test.
As usual, please leave a gentle comment should you spot any mistake in this set of suggested solutions.
Now to attend to the pile of comments *rubs eyes*
All the best for your remaining papers! Freedom (or the SAF) is near!
14 Comments
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Wah! I see my comment up there! Feeling like a celebrity LOL.
Anyway, thank you so much Mr Loi for taking painful time to upload the answers for H1 math. We really appreciate your effort :')
I'm so glad the Hypothesis testing method I did is correct! When my dad solved it, (he is a SAT math teacher) he put H1: u >300 so I thought I'd lose like 8m! Very happy now!
For qn 10, the last part, can we use bionomial distribution to solve it instead?
Thank you Mr Loi!
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@Michelle lee: Ok I'm back after a short hiatus!
For Q10(iv), yes you should get the same answer using the binomial distribution X ~ B (3, 0.62994) where the random variable X is the is the number of gardeners with > 75 plants that will flower. So,
P (X ≥ 2) = 1 − P (X ≤ 1) = ... using GC ... = 0.691
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Hi Mr Loi!
Thank you so much for taking the time to upload this! You've no idea how much this helps *-*
I just have a question to ask for Q11)!
Why is it that it is H1 : Mean ? The questions says "at least" which would mean that the length has to be 300 or MORE. This means we are testing if the claim of the average length being MORE than 300 is correct. Hence, if it were to be rejected, the average length would be 300 or less. Is it not...?
A minor thing to note, my teachers had told me previously that it was noted in Cambridge's marking report that we ought to state the relationship for the correlation between the two variables, so for 9ii) i think we'd need to add on something like "if the age of the car increases its advertised price will drop" to get a full 2m.
That's all! Thank you so much once again! (:
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@tere: If we reject and conclude that the mean is 300 or less, aren't we ignoring a part of the manger's claim that the mean can be 300? So I think it is not completely accurate...?
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@Michelle lee: mm i think my question was a little unclear because my signs were not included.
I was confused with his answer. I didn't understand why his H1:Mean was less than 300. I had put it the same as your dad, more than.
But right now, basing on what you're saying and looking at Mr Loi's solutions again, If we're testing it to be LESS THAN 300, then it would mean that we are testing if the average length of the ball is 300 or less than 300, and in this way we can still calculate and in fact it would be more accurate! Thank you, I understand now!
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@tere: Q11(ii) is a little tricky in the sense that you are actually testing for whether the average length is less than 300 m i.e.
Ho : μ = 0
H1 : μ < 300
In this case, if Ho is rejected ⇒ average length of string is less than 300 m which counters the manager's claim of at least 300 m.
Instead, if we were to test for H1 : μ > 300, accepting or rejecting Ho wouldn't make any difference in both cases since μ will still be within "at least 300 m" territory.
Q9(ii) Hmmm I'm inclined to think that a "strong negative linear correlation" would suffice to cover the "age of car increases/price decreases part" for the (presumably) 1-mark comment since the other mark would go towards the calculation of value of the coefficient. But who am I to go against Cambridge if it's true to markers' report said this!
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Despite the low demand for h1's answer, i want to express my biggest thank you for taking time to come out with the answers! thank you ^^!
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btw why is there a need to standardize the last qn? 😮 can't we just calculate the probability using normalcdf after obtaining the mean and variance?
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@abcd: It's perfectly fine not to standardize the normal distribution in Q12(ii). It's just a habit of mine from questions to find unknowns from given probability value(s) - which is not really necessary here 😛
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Wow my comment is up there too haha. Thanks for uploading the answers!
I just wanted to check, if I left my answers for Q8 (probability) in fractions, will I be penalized?
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@Adeline: No problem lah hehe
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Hi when will the 2013 a levels h1 math answers be uploaded?! Many of my school mates said it was a harder paper as compare to last years. Is it true? Really anxoous and worried. And normally what's the marks to get an A for h1 math. Is it around the 80s? Or 90s? Cos apparently for O levels Emaths is the high 90s to score an A1. :S
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will you upload for h1 maths 2014?:)
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@Annabelle:
