Q: Stating statistical hypotheses using sample statistics (such as the sample mean x-bar or the sample correlation coefficient r) instead of population parameters (such as mu or rho).

Always write hypotheses using population symbols (e.g., $ H_0: \mu_A = \mu_B $ and $ H_1: \mu_A \neq \mu_B $) or describe them strictly in words referencing the overall population parameter, never the sample statistics.

Q: Omitting the constant of integration (+c) when finding indefinite integrals (e.g., finding cost functions or plant growth functions from rates of change).

Always append $ +c $ to your integrated function immediately, then use the provided boundary/initial condition (such as $ h(2)=6.5 $ or $ C(500)=1750 $) to solve for the value of $ c $.

Question 1

Stating statistical hypotheses using sample statistics (such as the sample mean x-bar or the sample correlation coefficient r) instead of population parameters (such as mu or rho).

Accepted Answer

Always write hypotheses using population symbols (e.g., $ H_0: \mu_A = \mu_B $ and $ H_1: \mu_A \neq \mu_B $) or describe them strictly in words referencing the overall population parameter, never the sample statistics.

Question 2

Entering incorrect signs for cash flows (PV, PMT, FV) in the GDC Time Value of Money (TVM) financial solver, leading to math errors or impossible outcomes.

Accepted Answer

Apply strict cash-flow perspective: Cash inflows (loans received, withdrawals) are positive (+); cash outflows (deposits made, periodic payments) are negative (-).

Question 3

Rounding intermediate decimals too early in multi-step calculations, which leads to final answers falling outside the accepted range of the markscheme.

Accepted Answer

Store exact values in your GDC variables (e.g., A, B, C) or write down intermediate steps using at least 5-6 significant figures, rounding to 3 s.f. only on the final line.

Question 4

Leaving the GDC in the wrong angle mode (Radian instead of Degree, or vice-versa) when performing trigonometric geometry or calculus modeling.

Accepted Answer

Always check your GDC setting at the start of each problem. Use Degree mode for triangles, bearings, and basic spatial geometry. Use Radian mode for trigonometric calculus and tide models involving continuous cyclic functions.

Question 5

Writing final currency answers rounded to 3 significant figures rather than to exactly 2 decimal places as standard for monetary values.

Accepted Answer

When working with currency, round your final answer to exactly 2 decimal places (e.g., $5.58 or $86533.20) unless the question explicitly asks for a whole number.

Question 6

Writing coordinates (such as midpoints, vertices, or intersections on Voronoi diagrams) without surrounding parentheses, leading to an automatic accuracy penalty.

Accepted Answer

Ensure all spatial coordinates are written in proper coordinate format with enclosing brackets, for example: $ (8, 4) $ or $ (7, 3) $, instead of leaving them as plain numbers like '8, 4'.

Question 7

Failing to declare or compare p-values directly to the significance level during hypothesis testing conclusions.

Accepted Answer

Always write out the explicit mathematical inequality (e.g., $ 0.102 > 0.05 $ or $ p > 0.05 $) before stating whether you fail to reject or reject the null hypothesis.

Question 8

Omitting the constant of integration (+c) when finding indefinite integrals (e.g., finding cost functions or plant growth functions from rates of change).

Accepted Answer

Always append $ +c $ to your integrated function immediately, then use the provided boundary/initial condition (such as $ h(2)=6.5 $ or $ C(500)=1750 $) to solve for the value of $ c $.

Question 9

Attempting to reverse-engineer 'show that' questions by substituting target values back into the calculation instead of deriving them step-by-step.

Accepted Answer

Treat the target value in a 'show that' question as the finish line. Do not touch or use that number in your calculations; instead, write down each logical algebraic step starting from the raw formulas.

ฉบับ	เวลา	คะแนน	จำนวนข้อ	น้ำหนักคะแนน	ประเภทคำถาม
Paper 1	2ชม.	110	—	—	—
Paper 2	2ชม.	110	—	—	—
Paper 3	1ชม. 15นาที	55	—	—	—

Mathematics - Applications and Interpretation เคล็ดลับการสอบ

ภาพรวมข้อสอบ

โปรแกรมเครื่องคิดเลข

Graph: zeros, intersections & turning points

Numerical equation solver

Numerical integration & differentiation

Statistics & probability distributions

ข้อผิดพลาดที่พบบ่อย

เปลี่ยนเคล็ดลับให้เป็นเกรดดีเยี่ยม