Many birds are injured or killed by flying into windows. it appears that birds do not see windows. can tilting windows down so that they reflect earth rather than sky reduce bird strikes? researchers placed six windows at the edge of a woods: two vertical, two tilted downward 20 degrees, and two tilted downward 40 degrees. during the next four months, there were 53 bird strikes: 31 on the vertical windows, 14 on the 20‑degree windows, and eight on the 40‑degree windows.

why is a chi‑square procedure appropriate? sort the statements into those that are true for the above data and are also conditions for the chi‑square procedure, and those that are false. make sure you sort all the tokens into either the true or false category.

true vs. false

each observation falls into just one of the three categorical outcomes.

all observations are larger than 15 .

the deviations of observed counts from expected counts are not too small.

the probability of each categorical outcome is the same for each observation.

all observed counts are larger than five.

all observations are independent.

the expected counts are all 17.68 , greater than five.

there is a fixed number of 53 observations.

the sample size is larger than ten.