MIDTERM TEST # 2

QUESTIONS DRAWN FROM A SECOND MIDTERM EXAM

 

 

Question 1 Value 4

Your boss tells you that your company is about to launch a new drug product and that the food and drug administration will want to know what effect it has on blood pressure in males (only males take this drug). You are to do some tests that will establish the average increase in blood pressure that will be caused by the drug. You are also required to associate a particular 95% confidence interval with your estimate of the mean. Your boss tells you that she wants the confidence interval to be d = 2 pressure units (where d is 2 of the confidence interval). Finally she wants to know how much the testing is going to cost and to help you find out, she gives you a budget of $1000 which allows you to test 5 male volunteers. The data that you collect from these 5 men are: +12, +3, +10, +8, +4 blood pressure units. What will the entire test cost?

 

 

Question 2 Value 4

You want to know whether there is a significant difference in body length for humming birds taken from two islands. You visit a well known museum and you find 4 specimens from island #1 (lengths 4, 6, 4, 6, cm each) and 3 specimens from island #2 (lengths 6, 7, and 7 cm each). Setup a formal hypothesis test, do the appropriate statistical test and make an inference.

 

 

Question 3 Value = 4

You know that in the normal population, right-handed people outnumber left-handed people 9:1. You visit a small town in New Brunswick. You note that many people are left-handed. You think that the population of this small town might diverge from the normal human population by having more left-handed people than expected. To test this idea, you sample 10 people. You find that 4 of these people are left-handed and 6 are right-handed. Set up the formal hypotheses and use these data to test the validity of the null hypothesis.

 

 

 

Question 4 Value 4

You believe that coffee drinking raises heart rate. You test 6 people by measuring their normal heart rate, then giving them two cups of coffee and testing their heart rate 50 minutes after they have finished the last cup. The data are:

 

 

Person=s Name

 

Normal Rate

 

Rate 50 Minutes

After Drinking Coffee

Dave

John

William

Mary

Jo Lou Ann

Mick

70

60

80

75

75

50

80

65

90

65

80

52

 

 

 

Question 5 Value 4

In a lake the surface water is the epilimnion, the mid-depth water is the metalimnion and the deep cold water is the hypolimnion. Chaoborus are a type of zooplankton that migrate up and down through the water column. At night they move towards the surface to feed and during the day they go deep to avoid fish predators. This is called diel vertical migration.

You are a student studying this process in 10 lakes. You are told to expect that the Chaoborus will be deeper during the night than during the day. You visit each lake during the day and again during the night. You use an echosounder to record the depth of the Chaoborus. You get the following data:

 

 

Lake

 

Day Sample

 

Night Sample

 

A

 

metalimnion

 

metalimnion

 

B

 

hypolimnion

 

metalimnion

 

C

 

hypolimnion

 

metalimnion

 

D

 

hypolimnion

 

metalimnion

 

E

 

metalimnion

 

epilimnion

 

F

 

metalimnion

 

epilimnion

 

G

 

hypolimnion

 

epilimnion

 

H

 

metalimnion

 

metalimnion

 

I

 

hypolimnion

 

epilimnion

 

J

 

epilimnion

 

hypolimnion

 

 

 

Question 6 Value 4

You are a limnologist and you are asked to test the hypothesis that lakes that have low pH have lower fish biomasses than lakes with high pH. You sample a series of high pH lakes and a series of low pH lakes. You record fish numbers.

You find that the two lakes with the most fish are high pH lakes.

The one lake with the next most fish is a low pH lake

The one lake with the next most high pH

The two lakes with the next most are low pH

The three lakes with the next most are high pH

The four lakes with the next most are low pH

Establish formal hypotheses and test them in the space provided below. There are enough data provided here to do a full statistical test.

 

  

 

 

 

 

END OF MIDTERM #2


 

 

MIDTERM #2 SHORT ANSWERS.

 

QUESTION 1:

 

 

QUESTION 2:

 

 

 

QUESTION 3:

 

 

QUESTION 4:

 

 

QUESTION 5:

Correction: smallest sum= 2 (not 7 as indicated below)

 

 

QUESTION 6: