An agricultural company monitors the weight of crop yields.
The weight, XXX kg, of a sack of potatoes is modeled by a normal distribution with a mean of 25.4 and a standard deviation of 0.8.
Find the probability that a randomly selected sack of potatoes weighs exactly 25.4 kg.
Find the probability that a randomly selected sack of potatoes weighs more than 24.5 kg.
The weight, YYY kg, of a sack of onions is modeled by a normal distribution with mean μ\muμ and standard deviation σ\sigmaσ.
Given that P(Y<12.8)=0.9P(Y < 12.8) = 0.9P(Y<12.8)=0.9, show that
12.8−μ=1.282σ 12.8 - \mu = 1.282\sigma 12.8−μ=1.282σwhere the constant is given to three decimal places. Fully justify your answer.
Given further that P(Y<10.2)=0.05P(Y < 10.2) = 0.05P(Y<10.2)=0.05, find the values of μ\muμ and σ\sigmaσ.
48 exam-style questions on Edexcel A Level Maths 3.5 Finding the mean and standard deviation. Each one has a worked solution and a mark scheme showing where the marks go.