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2730 questions · page 93 of 137 · choose a topic above to narrow them down
SA-9709-P6-PO1-0022 marksL2 StandardCalculatorProbabilities
X∼Po(4.5). Find P(X<3), correct to 3 significant figures. Salam Academy Original Practice · Proposed mark scheme
SA-9709-P6-PO2-0023 marksL2 StandardCalculatorScaling λ
Breakdowns of a machine occur at random at an average rate of 0.8 per day. Find the probability of at most 3 breakdowns in a 7-day week, correct to 3 significant figures. Salam Academy Original Practice · Proposed mark scheme
SA-9709-P6-PO2-0052 marksL2 StandardCalculatorScaling λ
X∼Po(λ) and P(X=0)=0.2. Find λ, correct to 3 significant figures. Salam Academy Original Practice · Proposed mark scheme
SA-9709-P6-PO3-0072 marksL2 StandardCalculatorPoisson for binomial
1.5% of components are defective, independently. Use a Poisson approximation to find the probability that a box of 200 contains no defective components, correct to 3 significant figures. Salam Academy Original Practice · Proposed mark scheme
SA-9709-P6-SE-0013 marksL2 StandardCalculatorUnbiased estimates
A sample of 50 values gives Σ(x−20)=35 and Σ(x−20)2=1250. Find unbiased estimates of the population mean and variance (variance to 3 s.f.). 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-0044 marksL2 StandardCalculatorCI for a mean
A random sample of 40 has mean 72.4. The population standard deviation is 6. Find a 95% confidence interval for the population mean, with limits to 2 decimal places. Salam Academy Original Practice · Proposed mark scheme
SA-9709-P6-SE-0054 marksL2 StandardCalculatorCI for a proportion
In a random sample of 200 people, 48 are left-handed. Find a 90% confidence interval for the proportion of left-handed people, with limits to 3 decimal places. 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-SE1-0053 marksL2 StandardCalculatorUnbiased estimates
A random sample of 5 values is 3, 5, 6, 8, 8. Find unbiased estimates of the population mean and variance. 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-SE3-0023 marksL2 StandardCalculatorCI for a mean
A random sample of 36 from a population with standard deviation 15 has mean 120. Find a 90% confidence interval for the population mean, with limits to 2 decimal places. Salam Academy Original Practice · Proposed mark scheme
SA-9709-P6-SE3-0034 marksL2 StandardCalculatorCI for a proportion
In a random sample of 150 people, 60 prefer brand A. Find an approximate 95% confidence interval for the proportion of people who prefer brand A, with limits to 3 decimal places. Salam Academy Original Practice · Proposed mark scheme
SA-AB-AR-0032 marksL2 StandardCalculatorRQ
Calculate the RQ for tripalmitin: 2C51H98O6+145O2→102CO2+98H2O. Salam Academy Original Practice · Proposed mark scheme
SA-AB-AR-0041 markL2 StandardCalculatorRQ
An RQ of 1.0 indicates the substrate is
Salam Academy Original Practice · Proposed mark scheme
SA-AB-AR-0051 markL2 StandardCalculatorGlycolysis
In mammals, anaerobic respiration converts pyruvate to
Salam Academy Original Practice · Proposed mark scheme
SA-AB-BD-0012 marksL2 StandardCalculatorMeasuring
Counts of four species: 10, 20, 30, 40 (N = 100). Calculate Simpson's index D.
Salam Academy Original Practice · Proposed mark scheme
SA-AB-BD-0022 marksL2 StandardCalculatorMeasuring
50 snails are marked and released. Later, 40 are caught, of which 10 are marked. Estimate the population.
Salam Academy Original Practice · Proposed mark scheme
SA-AB-BD-0041 markL2 StandardCalculatorClassification
The correct order from largest to smallest group is
Salam Academy Original Practice · Proposed mark scheme
SA-AB-BD-0051 markL2 StandardCalculatorMeasuring
A belt transect is best for studying
Salam Academy Original Practice · Proposed mark scheme