Here are the weights, in kilograms, of five babies.
2.69
3.44
4.52
3.47
3.20
Find the standard deviation of these weights.
You must show your working.
Give your answer correct to 3 significant figures.
n=20n = 20n=20 ∑x=240\sum x = 240∑x=240 ∑x2=3000\sum x^2 = 3000∑x2=3000
Work out the standard deviation.
Give your answer correct to 3 decimal places.
n=15n = 15n=15
∑y=72 \sum y = 72 ∑y=72 ∑y2=396 \sum y^2 = 396 ∑y2=396Calculate the standard deviation.
Give your answer correct to 1 decimal place.
The number of errors, xxx, on each of 25 pages of a magazine were recorded.
Here are the summarised results.
∑x=195 \sum x = 195 ∑x=195 ∑x2=6840 \sum x^2 = 6840 ∑x2=6840Calculate the standard deviation of the number of errors.
Give your answers to 3 significant figures.
Some tigers were weighed. The mean weight of the tigers was 230 kg.
x x\,x kg represents the weight of a tiger where ∑x=3450\sum x = 3450∑x=3450
Work out how many tigers were weighed.
Given ∑x2=841,250\sum x^2 = 841,250∑x2=841,250, work out the standard deviation.
Here are the weights, in kilograms, of five babies.
2.69
3.44
4.52
3.47
3.20
Find the standard deviation of these weights.
You must show your working.
Give your answer correct to 3 significant figures.
Ted throws the javelin. The table gives information about the distances he threw the javelin last year.
| Distance (d d\,d metres) | Frequency |
|---|---|
| 0<d≤400 < d \leq 400<d≤40 | 25 |
| 40<d≤6040 < d \leq 6040<d≤60 | 36 |
| 60<d≤8060 < d \leq 8060<d≤80 | 14 |
| 80<d≤9080 < d \leq 9080<d≤90 | 5 |
Calculate an estimate for the mean distance.
Calculate an estimate for the standard deviation of the distribution. Give your answer correct to 1 decimal place. You may use ∑fd2=204,725\sum f d^2 = 204,725∑fd2=204,725.
Rebecca recorded the time she took to travel to the gym on each of 22 days. The table gives information about these times.
| Time (x x\,x minutes) | Frequency (fff) |
|---|---|
| 0<x≤50 < x \leq 50<x≤5 | 2 |
| 5<x≤105 < x \leq 105<x≤10 | 4 |
| 10<x≤1510 < x \leq 1510<x≤15 | 3 |
| 15<x≤2015 < x \leq 2015<x≤20 | 6 |
| 20<x≤2520 < x \leq 2520<x≤25 | 5 |
| 25<x≤3025 < x \leq 3025<x≤30 | 2 |
Calculate an estimate for the standard deviation of these times. You may use ∑fx2=6587.5\sum f x^2 = 6587.5∑fx2=6587.5.
The table gives information about the time spent, in minutes, by 50 people listening to the radio last Thursday.
| Time spent (x x\,x minutes) | Frequency |
|---|---|
| 0<x≤300 < x \leq 300<x≤30 | 12 |
| 30<x≤4030 < x \leq 4030<x≤40 | 25 |
| 40<x≤6040 < x \leq 6040<x≤60 | 8 |
| 60<x≤10060 < x \leq 10060<x≤100 | 5 |
Calculate an estimate for the mean time. You may use ∑fx=1855\sum fx = 1855∑fx=1855.
Calculate the estimate for the standard deviation of the distribution. Give your answer correct to 1 decimal place.
This table gives information about the distance, d d\,d km, travelled by each of 136 people to go to a music concert.
| Distance (d d\,d km) | Number of people (fff) |
|---|---|
| 40<d≤4540 < d \leq 4540<d≤45 | 6 |
| 45<d≤5045 < d \leq 5045<d≤50 | 19 |
| 50<d≤6050 < d \leq 6050<d≤60 | 53 |
| 60<d≤7060 < d \leq 7060<d≤70 | 37 |
| 70<d≤9070 < d \leq 9070<d≤90 | 15 |
| 90<d≤15090 < d \leq 15090<d≤150 | 6 |
Calculate an estimate for the mean distance.
Calculate an estimate for the standard deviation of the distances. Give your answer correct to 2 decimal places. You may use ∑fd2=552,756.25\sum fd^2 = 552,756.25∑fd2=552,756.25.
Practise Edexcel GCSE Statistics Standard Deviation with exam-style questions for Foundation and Higher tier. 10 questions, matched to the Edexcel GCSE Statistics (1ST0) specification and written in Paper 1 and Paper 2 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.