MHB Standard Deviation of Swim Times for King of the Hill Triathlon

AI Thread Summary
The King of the Hill triathlon in Kinsale includes a 750-meter swim, a 20-kilometer cycle, and a 5-kilometer run, with data from 224 athletes analyzed by Máire. Summary statistics show a mean swim time of 18.329 seconds, but the standard deviation for swim times is unknown. Participants are seeking assistance in estimating the swim's standard deviation, discussing formulas and alternative methods for calculation. The discussion highlights the importance of understanding variance and its relationship to standard deviation. Overall, the thread focuses on statistical analysis of swim times in the triathlon.
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The King of the Hill triathlon race in Kinsale consists of
a 750 metre swim, followed by a 20 kilometre cycle, followed
by a 5 kilometre run.
The questions below are based on the data from the 224
athletes who completed this triathlon in 2010.
Máire is analysing data from the race, using statistical
software. She has a data file with each competitor’s time
for each part of the race, along with various other details
of the competitors.
Máire gets the software to produce some summary statistics and it produces the following table.
Three of the entries in the table have been removed and replaced with question marks (?).

Swim Cycle Run
Mean 18.329 41.927 ?
Median 17.900 41.306 ?
Mode #N/A #N/A #N/A
Standard Deviation ? 4553 3409
Sample Variance 10.017 20.729 11.622
Skewness 1.094 0.717 0.463
Range 19.226 27.282 20.870
Minimum 11.350 31.566 16.466
Maximum 30.576 58.847 37.336
Count 224 224 224Estimate the standard deviation of the times for the swim. can someone help me answer this. do you use the forumula x-mean /standard deviation
 
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markosheehan said:
The King of the Hill triathlon race in Kinsale consists of
a 750 metre swim, followed by a 20 kilometre cycle, followed
by a 5 kilometre run.
The questions below are based on the data from the 224
athletes who completed this triathlon in 2010.
Máire is analysing data from the race, using statistical
software. She has a data file with each competitor’s time
for each part of the race, along with various other details
of the competitors.
Máire gets the software to produce some summary statistics and it produces the following table.
Three of the entries in the table have been removed and replaced with question marks (?).

Swim Cycle Run
Mean 18.329 41.927 ?
Median 17.900 41.306 ?
Mode #N/A #N/A #N/A
Standard Deviation ? 4553 3409
Sample Variance 10.017 20.729 11.622
Skewness 1.094 0.717 0.463
Range 19.226 27.282 20.870
Minimum 11.350 31.566 16.466
Maximum 30.576 58.847 37.336
Count 224 224 224Estimate the standard deviation of the times for the swim. can someone help me answer this. do you use the forumula x-mean /standard deviation

$$\text{variance} = (\text{standard deviation})^2$$
 
ok thanks and just wondering is their any other way of working it out do you know?
 

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