For 50 coded journey times, $x$ , the summary values are $∑x=815\sum x=815$ and $∑x2=16475\sum x^2=16475$ . The actual time, $t\,$ minutes, is related to $x\,$ by $t = 2 x + 20$ .

Calculate the mean and standard deviation of $x$ .

Hence calculate the mean and standard deviation of $t$ .

For 50 coded journey times, $x$ , the summary values are $∑x=815\sum x=815$ and $∑x2=16475\sum x^2=16475$ . The actual time, $t\,$ minutes, is related to $x\,$ by $t = 2 x + 20$ .

Calculate the mean and standard deviation of $x$ .

Hence calculate the mean and standard deviation of $t$ .

2 Statistics

Question 181

Markscheme

2 Statistics

Question 181

Markscheme

2 Statistics

Question 181

2 Statistics Questions

2 Statistics

Question 181

2 Statistics Questions