MS 150 Statistics q14 Name:

The number of steps for ten Mondays back in 2004 as recorded by a clip on pedometer are shown in the table.

Pedometer data
Mondays in 2004

For the number of footsteps on the ten Mondays above:

  1. _________ Determine the sample size n.
  2. _________ Calculate the sample mean x.
  3. _________ Calculate the sample standard deviation sx.
  4. _________ Calculate the z-score for 8200 steps per day.
  5. Construct a 95% confidence interval for the population mean µ steps for Mondays back in 2004. Use the sample size, sample mean and sample standard deviation to generate your t-critical tc and error tolerance E.
    1. __________ How many degrees of freedom?
    2. __________ What is tc?
    3. The error tolerance E = _______________
    4. The 95% confidence interval for the Monday mean µ is ____________ ≤ µ ≤ ____________
  6. __________ My 2008 population mean number of steps for any day of the week is 8200 footsteps. Based on the above data and a 95% confidence level, is the Monday mean from 2004 statistically significantly different at a confidence level of 95% from 8200 footsteps?
  7. __________ Using 8200 footsteps as the population mean to calculate the t-statistic .
  8. __________ Determine the p-value using the t-distribution.
  9. __________ What is the largest confidence interval c for which this change is statistically significant?
  10. _________________________________________________ Given a null hypothesis of H0: µ = 8200 and an alternate hypothesis of H1: µ ≠ 8200, would we reject the null hypothesis or fail to reject the null hypothesis that the sample could have come from that population at an α = 0.05.
  11. Hot off the press: Use the percentage and n given in the abstract PDF to create a 95% confidence interval for the proportion of students 14 to 17 years old on Pohnpei who intentionally injure themselves. Run two confidence intervals, one for the boys and one for the girls. Report whether the two proportions are statistically separated. Also note what is the meaning for the "P<0.05" for those groups most often reporting intentional injury.

The above report adds to a prior finding regarding obesity in the FSM that put the FSM at number two on the planet for percent of the population with a BMI over 25. While obesity is problematic across Micronesia, Kosrae came in for special attention in one study. See also [01] [02] [03]

Shortly after topping the obesity charts, the FSM was ranked number two for marijuana usage in a UN drug report as reported in the Kaselehlie Press.