For Thursday:
DRP scores for third graders
Treatment group
24 43 58 71 43 49 61 44 67 49 53 56 59 52 62 54 57 33 46 43 57
Control group
42 43 55 26 62 37 33 41 19 54 20 85 46 10 17 60 53 42 37 42 55 28 48
Moon data
(as a .csv file below)
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from Wednesday
mountain lion weights
68 104 128 122 60 64
1) Blissymbols are pictographs used to help leaning-disabled children. In a study of computer assisted learning, 12 normal-ability schoolchildren were assigned randomly to each of four different computer learning programs. After they used the program they were quizzed on how many of the 24 pictograms they could recognize. One of the four computer learning programs had the following results:
12, 22, 9, 14, 20, 15, 9, 10, 11, 11, 15, 6 [this is the number they got right]
3) Prehistoric Miniature Horse! so this archaeologist totally finds these bones from a new typ of prehistoric miniature horse. And he totally asks you to help him figure out what the mean shoulder height of this new horse is [the archaeologist is totally willing to name the horse after you if you want]. Here is the shoulder heights of the bones he's found thus far:
45.3, 47.1, 44.2, 46.8, 46.5, 45.5, 47.6,
2) Ancient air. The composition of the earth's atmosphere may have changed over time. To try to discover the nature of the earths atmosphere long ago, we try to examine the gas in bubbles inside the ancient amber. The gas has been trapped (by estimates at least) an average of 75 to 95 million years.
Below is the percent of nitrogen that is stored in these samples air bubbles:
63.4, 65.0, 64.4, 63.3, 54.8, 64.5, 60.8, 49.1, 51.0
The air currently has a percent of 78.1 nitrogen. [according to wikipedia]
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From January 3:
1. Hail damage. You work for an insurance company and are put in charge of determining rates for hail insurance--specifically wheat crops. Believe it or not, hail damage is a fairly large problem for crops--nationally, 11% of all wheat crops are destroyed by hail (I know, right?) You are going through some claims for a county in Colorado and get the following claims for percentage of destruction:
15, 8, 9, 11, 12, 20, 14, 11, 7, 10, 24, 20, 13, 9, 12, 5
Your job is to determine if there is more crop damage in this county than the normal average--if there is you are going to raise the rates for insurance for the following years. Assume at the national sd is 5%.
a. Give a null and alternative hypothesis.
b. In order to validate your raising rates, you need to be 99% confident that the damage here is more than the national average. Should you raise your rates? Explain.
2. I've created New Newt-Salve 2000!--a salve that when applied to newts should help with their healing times when we cut them and then watch them heal. I catch a bunch of newts and then test the salve on them. Their healing rates are as follows:
34 28 16 40 29 20 42 19 36 38 21 39 43 48 18 37 27 49 32 23
Run the appropriate tests and see whether or not New Newt-Salve 2000! is actually doing what it claims it should do.
[as a reminder, our newts without salve had a healing rate of 25.7 and sd of the population is 8]
3. So . . . sun spots. We've looked for them for generations, and it has been believed that the mean number of sunspots in an average four week period is 41, with a standard deviation of 35. We've been looking at the numbers over the past four years (plus a little):
12.5 14.1 37.6 48.3 67.3 70.0 43.8 56.5 59.7 24.0 12.0 27.4 53.5 73.9 104.0 54.6 4.4 177.3 70.1 54.0 28.0 13.0 6.5 134.7 114 72.7 81.2 24.1 20.4 13.3 9.4 25.7 47.8 50.0 45.3 61.0 39.0 12.0 7.2 11.3
Why do we care? Well, it appears that when the average number of sunspots over a longish period of time is above the mean, it can produce times of general warming on the Earth. My question is: do we have enough evidence here to claim that we might be in for a time of warming on the Earth due to fluctuations in the sun? Give a null and alternative hypothesis, give an appropriate level of significance, etc. etc.
4. A school district is trying to prove that they have smarter third graders than the average. One way to do that is to look at the scores on a nationwide test. On this test, the national mean is 32, and the sd is 11. Below are the scores for 44 students in the district.
a. Give a null and alternative hypothesis
b. Run the tests and determine if the third graders in this district could be considered to be smarter. Give your numbers, a reason and a conclusion.
40 26 39 14 42 18 25 43 46 27 19 47 19 26 35 34 15 44 49 38 31 46 52 25 35 35 33 29 34 41 49 28 52 47 35 48 22 33 41 51 27 14 54 45