The random variable XXX has a normal distribution with mean 12 and standard deviation 4.
Find P(X<14)P(X < 14)P(X<14).
Find the value of kkk such that
P(12−k<X<12+k)=0.80 P(12 - k < X < 12 + k) = 0.80 P(12−k<X<12+k)=0.80A single observation xxx, of XXX, is to be taken. A rectangle is drawn on a centimetre grid with vertices having coordinates (0,0)(0, 0)(0,0), (x,0)(x, 0)(x,0), (x,x−4)(x, x-4)(x,x−4) and (0,x−4)(0, x-4)(0,x−4).
Find the probability that the area of this rectangle is more than 45 cm245\text{ cm}^245 cm2.
616 exam-style questions on Edexcel A Level Maths The Normal Distribution, covering 3.1 The Normal Distribution, 3.2 Finding Probabilities for Normal Distributions, 3.3 The Inverse Normal Distribution Function, 3.4 The Standard Normal Distribution, 3.5 Finding the mean and standard deviation, 3.6 Approximating a Binomial Distribution, and 3.7 Hypothesis Testing with the Normal Distribution. Each one has a worked solution and a mark scheme showing where the marks go.