CAIE S1 2020 June — Question 1 3 marks

Exam BoardCAIE
ModuleS1 (Statistics 1)
Year2020
SessionJune
Marks3
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicMeasures of Location and Spread
TypeCalculate mean from coded sums
DifficultyEasy -1.8 This is a straightforward algebraic manipulation of the coding formula Σ(x-50) = Σx - 50n, requiring only one step to solve for n. It tests basic understanding of summation notation with no conceptual difficulty or problem-solving required.
Spec2.02g Calculate mean and standard deviation

1 For \(n\) values of the variable \(x\), it is given that $$\Sigma ( x - 50 ) = 144 \quad \text { and } \quad \Sigma x = 944 .$$ Find the value of \(n\).

Question 1:
AnswerMarks Guidance
AnswerMarks Guidance
\(\sum x - 50n = 144\)B1
\(50n + 144 = 944\)M1
\(n = 16\)A1
Total3
## Question 1:

| Answer | Marks | Guidance |
|--------|-------|----------|
| $\sum x - 50n = 144$ | B1 | |
| $50n + 144 = 944$ | M1 | |
| $n = 16$ | A1 | |
| **Total** | **3** | |

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1 For $n$ values of the variable $x$, it is given that

$$\Sigma ( x - 50 ) = 144 \quad \text { and } \quad \Sigma x = 944 .$$

Find the value of $n$.\\

\hfill \mbox{\textit{CAIE S1 2020 Q1 [3]}}