40 or 400 which has greater standard deviation?

In summary, the conversation discusses the expected standard deviation of tossing two coins simultaneously 400 times and whether it would be greater or less than if they were tossed 40 times. The speaker believes that the larger sample size would result in a greater standard deviation due to a wider range of possible outcomes. However, they also mention that the standard deviation expressed as a fraction of the average would be less for 400 tosses compared to 40 tosses. The speaker also expresses their lack of confidence in probability.
  • #1
aisha
584
0
If you tossed two coins simultaneously 400 times, would you expect the standard deviation to be greater or less than it was 40 times?

I think tossing 2 coins 400 times would give a greater standard deviation because the sample size is larger so the standard deviations can be quite far from the mean?

Im not sure if that makes sense PLZ HELP! I am not good at probability. :cry:
 
Physics news on Phys.org
  • #2
aisha said:
If you tossed two coins simultaneously 400 times, would you expect the standard deviation to be greater or less than it was 40 times?

I think tossing 2 coins 400 times would give a greater standard deviation because the sample size is larger so the standard deviations can be quite far from the mean?

Im not sure if that makes sense PLZ HELP! I am not good at probability. :cry:
I am not sure what you mean by the standard deviation of tossing a coin 400 or 40 times. If you tossed the coins in groups of 40 and did that N times, the average would be very close to 20 heads every 40 tosses and the standard deviation would be the square root of the sum of the squares of all the deviations from 20.

So the standard deviation for 400 would have to be greater than for 40 but expressed as a fraction of the average (ie. 200 or 20 respectively), it would be less.

AM
 
  • #3


Your reasoning is correct. In general, as the sample size increases, the standard deviation also tends to increase. This is because larger sample sizes allow for more variation in the data, which can lead to a wider spread of values around the mean. In the case of tossing two coins, with a larger sample size of 400, there is a higher likelihood of getting different combinations of heads and tails, leading to a greater standard deviation compared to a sample size of 40. So, in this scenario, we would expect the standard deviation to be greater when tossing two coins 400 times compared to 40 times.
 

1. What is standard deviation and why is it important?

Standard deviation is a statistical measure that describes the spread or variability of a set of data. It tells us how much the data values deviate from the mean. Standard deviation is important because it allows us to understand the distribution of the data and make comparisons between different data sets.

2. How do you calculate standard deviation?

To calculate standard deviation, first find the mean of the data set. Then, for each data point, subtract the mean and square the result. Next, find the sum of all the squared differences and divide it by the total number of data points. Finally, take the square root of this value to get the standard deviation.

3. Which data set would have a greater standard deviation - 40 or 400?

In general, a larger data set would have a greater standard deviation because there is a greater range of values. However, it is not solely dependent on the size of the data set and can also be affected by the distribution and variability of the data.

4. How does standard deviation relate to the mean?

Standard deviation and mean are both measures of central tendency, but they describe different aspects of the data. The mean tells us the average value of the data, while the standard deviation tells us how much the data deviates from the mean.

5. What are the limitations of using standard deviation?

Standard deviation is affected by extreme values or outliers in the data, which can skew the results. Additionally, it is a measure of spread and does not provide information about the shape of the data distribution. Therefore, it should be used in conjunction with other measures and visualizations to fully understand the data.

Similar threads

  • Calculus and Beyond Homework Help
Replies
4
Views
1K
  • Set Theory, Logic, Probability, Statistics
Replies
24
Views
3K
  • Introductory Physics Homework Help
Replies
7
Views
2K
  • Set Theory, Logic, Probability, Statistics
Replies
19
Views
2K
  • Set Theory, Logic, Probability, Statistics
Replies
6
Views
3K
  • Set Theory, Logic, Probability, Statistics
Replies
21
Views
3K
  • Introductory Physics Homework Help
Replies
1
Views
553
  • General Math
Replies
1
Views
1K
  • Set Theory, Logic, Probability, Statistics
Replies
6
Views
1K
Back
Top