The recovery time of biological tissue following a specific laser treatment, T T\,T milliseconds, is modeled by a normal distribution such that T∼N(140,152)T \sim N(140, 15^2)T∼N(140,152).
Find P(T<110)P(T < 110)P(T<110).
In a batch of 600 treatment sessions, determine the expected number of sessions where the recovery time is less than 110 ms.
Determine the value of ttt, to 2 decimal places, such that P(T<t∣T>110)=0.8250P(T < t \mid T > 110) = 0.8250P(T<t∣T>110)=0.8250.
390 exam-style questions on OCR A Level Maths 2.4 Statistical Distributions, covering 2.4.1 Discrete probability distributions, 2.4.2 Binomial distribution as a model, 2.4.3 Calculating binomial probabilities, 2.4.4 Mean and variance of the binomial (A-level only), 2.4.5 Normal distribution as a model (A-level only), 2.4.6 Probabilities using the normal distribution (A-level only), 2.4.7 Links to histograms, mean and standard deviation (A-level only), and 2.4.8 Selecting an appropriate distribution (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.