# 101 Speed of Sound 20 March 2015

Speed of Sound (m/s)
326
329
326
352
348
348
323
365
342
341

The SC 130 Physical Science students used a new procedure to measure the speed of sound. For ten different distances the class measured the difference in time between seeing boards clap and hearing the sound of the clap. The 8:00 class would successfully measure sound speeds from distances of 209 meters to 455 meters. The 11:00 laboratory section would measure sound speeds across distances ranging from 223 meters to an amazing 514 meters. At these distances seeing the person clapping the boards was difficult. 514 meters is more than half a kilometer. For further explanation of the experiment, see the blog article on measuring the speed of sound.

Use the sound speed data in the table above for this quiz.

1. Calculate the sample size n: _
2. Calculate the sample mean x: _
3. Calculate the sample standard deviation sx: _
4. Calculate the standard error SE of the sample mean x: _
5. Calculate tcritical for a confidence level c of 95%: _
6. Calculate the margin of error E for the sample mean x: _
7. Calculate the lower bound for the 95% confidence interval for the mean: _
8. Calculate the upper bound for the 95% confidence interval for the mean: _
9. At 30 °Celsius the speed of sound is 349.2 m/s. Does the data include 349.2 m/s in the 95% confidence interval?
10. Can you reject a sound speed of 349.2 m/s based on this data, or does the data support a sound speed of 349.2 m/s?