Numerically Summarizing Data

3.1

mean: $2025.25 median: $2209 mode: no mode

mean: $41.41 median: $40.76 mode: no mode

mean: 3670 psi median: 3830 psi mode: 4090 psi

mean:266 min median: 266 min mode: 260 min

  1. the mean is approximately greater than the median, because this graph is skewed to the right.

  2. the mean is approximately equal to the median, because this graph is bell curved.

  3. the mean is approximately less than the median, because this graph is skewed to the left.

3.2

  1. the sample variance is 36 and the standard deviation is 6.

  2. the sample variance is 8152.225 and the standard deviation is 10.

  3. the population variance is 16 and the standard deviation is 4.47.

  4. the population variance is 64 and the standard deviation is 8.49.

  5. the sample variance is 196 and the standard deviation is 14.

  6. the population variance is 25 and the standard deviation is 5.48.

  7. the range is 25 min and the sample sample deviation is 8.43.

  1. the sample standard deviation is 6

  2. the histogram is most likely bell shaped shaped, so the use of the empirical rule is appropriate

  3. about 95% of eruptions last between 92 and 116 seconds

  4. 93.2% is the actual percentage of eruptions that last between 92 and 116 seconds

  5. about 15% of eruptions last less than 98 seconds

  6. 11.4% of eruptions last less than 98 seconds