NAME DAT ANALYSIS
NAME DAT ANALYSIS
NAME DAT DF
DA Z? DA T? DISTRIBUTION
BONUS TREATS YUM
100
The babies born in singleton births in the United States have birth weights that are approximately normally distributed with mean 3.296 kg and standard deviation 0.56 kg (Martin et al. 2011). You look at a sample of 20 babies that were born in a drought year in the U.S., and find the average of this sample to be 3.21kg. Did the drought seem to affect the weight of babies under normal conditions?
What is a normal distribution?
100
What is an Odds-Risk?
100
Paired t-test
What is DF = # pairs - 1 ?
100
Explain to the class the difference between a paired and unpaired test.
Paired: uses same individuals for multiple treatments / both treatments applied to each sampled unit
Unpaired: tests if the means of two groups do not differ when there is no natural pairing of samples
200
Researchers found that 6101 of the 9821 slices of toast
thrown in the air landed butter side down.
Does this data suggest that butter on one side of the toast changes its chances of falling on one side or the other?
What is a binomial distribution?
200
In garter snakes, some males emerging from overwintering dens mimic females by producing female pheromones. Does this influence whether these males attract more males? Observations in Manitoba found that on average, 58% of a male’s body that mimicked females was covered by other males (sd= 28%, n = 10) while 25% of non-female mimic’s body was covered (sd = 24%, n = 19).
What is an unpaired t-test?
200
Chi-Squared Goodness of Fit
What is DF = n - 2 ?
300
Wilson et al. 2011 followed a set of male health professionals for 20 years. Of all the mean in the study, 7,890 drank no coffee and 2,492 drank on average more than six cups per day. In the “no- coffee” group, 122 developed advanced prostate cancer, and 19 in the “high-coffee” group did.
What is an Odds-Risk?
300
As the world warms, geographic ranges of species might shift towards cooler areas. Chen et al. 2011 studied recent changes in the highest elevation at which species occur. Is there reason to believe that species are shifting? Xbar = 15.329°, s = 30.662, n = 31
What is a One-sample t-test?
300
Chi Squared Independence
What is DF = (r - 1) * (c - 1) ?
300
I ran an Odds-Risk Ratio to see if a consistent diet of bananas turns one into a Minion and calculated an OR of 1.45.
What indicates that one is much more likely to turn into a Minion if they maintain a consistent diet of bananas?
400
What is the association between degree of infection and rate at which killifish were preyed on?
What is a Chi-Squared Independence?
400
Unpaired t-test (HINT: don't even bother trying to calculate it...)
For what test will the DF be provided for?
400
s = 5.3 n = 25 Xbar = 254
What is a T-distribution?
500
Dung beetles are one of the most common prey for burrowing owls. Burrowing owls will collect bits of mammal dung and leave them around the owls’ burrows, luring their prey towards them. A research team wanted to know whether this method actually worked. They added dung around 10 owl burrows, and nothing around another 10 owl burrows, and recorded the average number of beetles consumed over the next few days.
What is an unpaired t-test?
500
Fires are a common and important part of many ecosystems, of which many species have evolved adaptations to avoid. Reed frogs in West Africa have been observed to hop away from grass fires long before the flames come near them, suggesting that frogs may be able to hear the fire. In a study, 60 frogs were equally placed into 3 groups: 1 exposed to the sound of fire, 1 exposed to the fire sounds played backwards, and 1 to white noise. Of the 60 frogs, 18 hopped away from the sound of fire, 6 hopped away from the fire sounds played backward, and 0 hopped away from white noise.
What is a Chi-Squared Independence?
500
Confidence interval, one-sample t-test, f-test
What is DF = n - 1 ?
500
𝜎 = 2.9 n = 12 Xbar = 5.2
What is a Z-distribution?