To investigate, Lesku et al. (2012) measured the activity patterns of breeding pectoral sandpipers (Calidris melanotos) in the high Arctic in summer, when the sun never sets. The accompanying figure shows the observed percent time that individual males were awake and active in a 2008 field study. The data are on the left. To the right of the data are the sample mean (filled circle) and error bars for the standard deviation, the standard error of the mean, and a 95% confidence interval for the mean (in no particular order).

a. Which of the error bars indicates the standard deviation?

b. Which error bar indicates the standard error of the mean?

c. Which error bar indicates a 95% confidence interval for the mean?

d. Estimate by eye the smallest plausible value for the mean activity (% time) of male pectoral sandpipers. Using this smallest plausible value, calculate approximately the maximum
plausible number of hours (out of 24 hours) that males spend inactive or asleep.

95 80 75 70 Data A Avtivity (% time) B.