Adult Male Polar Bears Are Expected to Weigh, on Average

Short Answer

Adult male polar bears are expected to weigh, on average, 370 kg. A polar bear's primary source of food are seals and other marine animals, which they hunt from a platform of sea ice. Scientists are concerned that global warming is melting these platforms earlier in the year, reducing the time polar bears are able to hunt and forcing them inland without the necessary fat reserves built up to survive summer and fall. The US Geological Survey (USGS) conducted a study in the Southern Beaufort Sea to investigate whether climate change has appeared to negatively impact the weight of polar bears. Eighty-three adult male polar bears were captured between March and May of the years 1990 and 2006 and their weights were recorded. The sample mean weight was 324.6 kg, the sam-ple median weight was 339.4 kg, and the sample standard deviation was 88.3 kg. A box plot of the data is shown below.
-The mean weight in the data set is 324.6 kg, the median weight is 339.4 kg, and the sample standard deviation is 88.3 kg. Which of the following statements do we know to be true based on these values alone?
The average weight of all adult male polar bears in the Southern Beaufort Sea is 324.6 kg. ______ (1)
The distribution of weights in the sample is roughly symmetric, since the mean and median are close relative to the size of the standard deviation.______ (2)
There is evidence that the average weight of an adult male polar bear in the Southern Beaufort Sea is less than 370 kg.______ (3)
On average, each adult male polar bear captured weighed 88.3 kg more or less than 324.6 kg.______ (4)
Drop-down options for (1), (2), (3), (4):
•True
•False