PractiseQuestion bank
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12 questions
SA-9709-P6-SE-0091 markL1 FoundationCalculatorCLT
The Central Limit Theorem says that, for a large sample from any population with mean μ and variance σ2, Salam Academy Original Practice · Proposed mark scheme
SA-9709-P6-SE2-0013 marksL1 FoundationCalculatorNormal sample means
X∼N(60,16). A random sample of 4 observations is taken. Find P(Xˉ<57), correct to 3 significant figures. Salam Academy Original Practice · Proposed mark scheme
SA-9709-P6-SE2-0021 markL1 FoundationCalculatorCLT
A population has standard deviation 10. Find the standard deviation of the mean of a random sample of 25. Salam Academy Original Practice · Proposed mark scheme
SA-9709-P6-SE2-0051 markL1 FoundationCalculatorCLT
In which situation is the Central Limit Theorem needed?
Salam Academy Original Practice · Proposed mark scheme
SA-9709-P6-SE-0023 marksL2 StandardCalculatorNormal sample means
X∼N(100,152). A random sample of 25 is taken. Find P(Xˉ>104), correct to 3 significant figures. Salam Academy Original Practice · Proposed mark scheme
SA-9709-P6-SE-0033 marksL2 StandardCalculatorCLT
A population (not necessarily normal) has mean 50 and standard deviation 8. A random sample of 64 is taken. Find, approximately, P(Xˉ<48.5), correct to 3 significant figures. Salam Academy Original Practice · Proposed mark scheme
SA-9709-P6-SE-0112 marksL2 StandardCalculatorCLT
X has standard deviation 12. Find the standard deviation of the mean of a random sample of 36 values. Salam Academy Original Practice · Proposed mark scheme
SA-9709-P6-SE2-0033 marksL2 StandardCalculatorCLT
A population with an unknown distribution has mean 30 and standard deviation 6. A random sample of 50 is taken. Find, approximately, P(Xˉ>31), correct to 3 significant figures. Salam Academy Original Practice · Proposed mark scheme
SA-9709-P6-SE2-0043 marksL2 StandardCalculatorNormal sample means
X∼N(200,252). A random sample of 16 is taken. Find P(195<Xˉ<205), correct to 3 significant figures. Salam Academy Original Practice · Proposed mark scheme
SA-9709-P6-SE2-0062 marksL2 StandardCalculatorNormal sample means
A population has standard deviation 7. Find the smallest sample size n for which the standard deviation of Xˉ is less than 1. Salam Academy Original Practice · Proposed mark scheme
SA-9709-P6-SE2-0082 marksL2 StandardCalculatorNormal sample means
X∼N(μ,9). A random sample of 36 is taken. Find the probability that Xˉ is more than 1 above μ, correct to 3 significant figures. Salam Academy Original Practice · Proposed mark scheme
SA-9709-P6-SE2-0074 marksL3 ExamCalculatorCLT
X∼Po(4). A random sample of 40 observations is taken. Use a suitable approximation to find P(Xˉ>4.5), correct to 3 significant figures. Salam Academy Original Practice · Proposed mark scheme