A high-precision voltage regulator is tested for drift during calibration. In each micro-adjustment step, the voltage deviation VVV is an integer millivolt value where V∈{−3,−1,1,3}V \in \{-3, -1, 1, 3\}V∈{−3,−1,1,3}, with each value being equally likely.
Determine the mean and the variance of VVV.
A sequence of 150 independent micro-adjustments is performed. Using the Central Limit Theorem, calculate an approximation for the probability that the average voltage deviation of these 150 adjustments is less than -0.25.
390 exam-style questions on OCR (MEI) A Level Maths 2.4 Probability Distributions, covering 2.4.1 Recognise binomial situations, 2.4.2 Probability of success p, 2.4.3 Calculate binomial probabilities, 2.4.4 Mean of the binomial distribution, 2.4.5 Expected frequencies for binomial, 2.4.6 Probability functions and discrete random variables, 2.4.7 Numerical probabilities for a simple distribution, 2.4.8 Normal distribution as a model (A-level only), 2.4.9 Shape of the Normal curve (A-level only), 2.4.10 Linear transformation and standardising (A-level only), 2.4.11 Symmetry and inflection of Normal curve (A-level only), 2.4.12 Calculate probabilities from a Normal distribution (A-level only), 2.4.13 Model with probability distributions, and 2.4 Probability Distributions. Each one has a worked solution and a mark scheme showing where the marks go.