PART 1 - Problems
1) Calculate by hand, the following descriptive statistics (use formulas from your book needed):
211, 315, 265, 420, 350, 250
Mean ___(2) Standard deviation ___(2)
Standard error of mean ___(2) Coefficient of miation ___(2)
2) Determine the mode and median the the following obsenations: (4) Mode Median
3) Calculate (by hand) the probability of having three girls In a family of 5. ____(6)
4) In 100 pitfall traps In the Smoky Mountains, an ecologist collects the following data for an endangered species of purse-web spider.
# spiders #sweeps Obsereved
0 77
1 17
2 5
3 3
a) Calculate (by hand) the observed and expected probability distribution for these data. Show work below.
b) Use the appreprlate statistical test (in Minitab) and explain If the spiders follow the predicted distribution or not. If not how do they differ from the predicted distribution?
5) Using Minibab (descriptive statistics) and the appropriate equation and table In the book, calculate the 99% confidence limits for the sample mean of bass lengths (Minitab "3.2 Bass Lengths")
x¯=
Sx¯ =
t(0.01, n-1) =
Confidence Limits =
for all problems bele., revolt all tbe relevant statistics and fully Inhume: and explain Una bkNook4 OgattilffilereVELOSO, Use the hlialtab worl.heet file, VsesdassasrpDate.mtws for problems 6-9.
6) Choose the appropriate parametric statistical test to compare the mean number of pseudoscornions among the three treatments, ambient (amb), wet, and dry. What Is the mean for each treatment?
7) Compare the means (again, choosing a parametric test) of the November and August samples of pseudoscorpions.
8) Revisit question #6. Test the data on pseudoscasplons for normality and equality of variance. If the data are not appropriate fun parametic test (fall either test), use the appropriate non-pammetho test to answer question 01 and report your findings here.
9) Choose the appropriate statistical test to explore the relationship (if any) between the number of pseudoscorpions and the number of spiders on the plots. Create an appropriate graph, print and attach it to this exam.
10) A Merck scientist wants to ensure that Fosamax weekly tablets always contains 70.0 mg of active ingredient. He takes a sample of 15 pills from the production line. Can the managing scientist be assured in the quality of pills he is turning out? (Minitab worksheet "Fosamax").
11) An entomologist is interested in the ability of an insect pest to withstand starvation under different conditions of ambient humidity, suspecting that at lower humidity the beetles will desiccate more rapidly and die. He starves beetles for six days under different humidity and records the amount of weight loss in mg. He knows that a 25% weight loss (beetles weigh on average 10 mg) is fatal. Predict at what level of humidity all of his beetles will die.
12) A young mkrobrologIst surveyed different surfer. In public restaurants to determine if there were differences in the level of bacterial contamination.
What is the independent variable?
What is the response variable?
What type of data is the response variable? Would parametric tests be appropriate? What kind?
13) Crarnar (2008) found that Prow? recluses preferred live over dead prey = (X2 = 12.0, P = 0.0005). On a sentence, explain precisely what the P value means - In your own words, Rot from the book.
Types of Data and Scales of Measurement - Indicate the data type and scale of measurement In the blank next to each description, in that order.
14) The lengths of male and female spiders
15) Number of male and female fleas on a dog
16) Intensity of breast color on goldfinch., from 1-5
17) Red and gray color phases of screech owls
18) Dissolved oxygen levels at flue depths in a lake
Choose the appropriate test- Assume that measurement data (dlscrete a continuous) are normal unless otherwise indicated.
19) An epidemiologist compares the effectiveness of three drugs in controlfing the level of malarial infection. He ranks the level of infection from 1-5.
20) A free-range pig farmer wants to assure her consumers het her bacon contains no more than 5 ppb of nitrates (used In the smoking vote.).
21) A state deer biologist wants to know what effect three different management techniques have on the size of deer populations.
22) A food scientist wants to see If a new additive will lower the grams of fat in Little Debbie snack cakes.
23) A psychiatrist's bolting for early indicators of anxiety In her patents. She randomly samples patient in her community and looks at their age, sec, marital status and checks to sae If and how they are easeated with self-reported arodety.
24) A pharmaceutical firm wants to show that their new drug will redure secretly of migraine headaches. Patient rate the severity of their migraines on a scale of 1-7 before they receive the drug and again after 4 weeks of taking the drug.
25) A breeder of champion hedgehogs is interested in determining-how much of the variation in spine density is caused by the percentage of fat in their mother's diet. She puts mama hedgehogs on 6 - different levels of fat diets and measures the density of their offspring's spines at maturity.
26) Describe the difference between a Mann Whitney and a Wilcoxen
27) Describe the difference between a one tailed and two-tailed T test.
28) Describe the difference between a one population (one-sample) and two population (two-sample) T test.