Question

As the Arctic warms and winters become shorter, hibernation patterns of archic mammals are expected to change Sheriff ot al (2011) nvestigated emergence dates from hibernation of arctic ground squirrels at sites in the Brooks Range of northern Alaska The measurements shown in the following tigure are emergence dales in a sample of male and female ground squirrels at one of their study sites 10- 08 0.6 2 04 0.2 0.0 Males 26 31 5 10 15 20 25 30 March April Date of emergence What type of graph is this? cumulative distribution The date at which cumulative frequency reachos 0 50 is the Which sex has the earliest median emergence date? Which sex has the greater IQR? Which sex has an approximate IQR of 8 days? which sex has an approximate IQR of 4 days? (mean, median, or mode

Answer 1

• The data at which cumulative frequency reaches 0.50 is the median (median is found be ordering the data sets and selecting the one in the middle; mean however is average of the data sets; mode is the most repeated data point).
• The female sex has the earliest median emergence date ( draw a line from the y axis at 0.50 and extend it towards the x axis and then check the corresponding date on the x axis).
• IQR stands for interquartile range, which is the midspread or middle 50%. By drawing a line from the y axis at 0.50 and extending it toward the x axis, it would appear that the female sex has a greater IQR in comparison with the male sex.
• The female sex has an approximate IQR of 8 days (as shown by the horizontal lines in the graph).
• The male sex has an approximate IQR of 4 days (as shown by the horizontal lines in the graph).