(main)[3]
Determine the probability that the mean number of characters in a random sample of 100 emails sent by the company is greater than $1300$.
Mathematics 9709 · AS & A Level · Sampling and estimation
Sampling and estimation — practice question
The distribution $N(1250, 480^2)$ is used to model the number of characters in emails sent by a particular company.
Worked solution & mark scheme
This 3-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Apply standardisation using $z=\frac{1300\pm\frac{1}{200}-1250}{\frac{480}{10}}$ or $z=\frac{1300-1250}{\frac{480}{10}}$” …
- Full mark scheme, point by point
- Step-by-step worked solution
- Write your answer & get it marked instantly by AI