objective: students will experiment with different  ways to do a random sample and discuss  human bias.

objective: students will experiment with different ways to do a random sample and discuss human bias.
Jelly Blubber Colony­ experiment.
You will have 30 sec to choose 10 jelly fish that are most representative of the whole group ­ in terms of size.
Circle the 10 jelly fish you feel represent the size of the colony the best.
For each of the jelly fish that you chose, find the "blubber number" on the other side of the worksheet and record its length. Average (find the mean of) the ten lengths.
Place your mean/average on the dot plot in the front of the room.
10
10
12
14
16
18
20
22 24
26 28
30
32 34 36 38 40 42 44
12
14
16
18
20
22 24
26 28
30
32 34 36 38 40 42 44
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II. Now we will let our calculators choose for us.
Math ­ Prb ­ 5) randint (1, 100) hit enter and write down the number the calculator selects. Do this 9 more times.
Find the average/mean length of the 10 jelly fish that the calculator selected.
Place a dot above the average length on the dot plot.
III. The real mean. Because we have calculated the lengths of all 100 jelly fish it is possible to find the real mean/average of the colony.
Use your graphing calculator to find the real mean.
I. Stat­ edit ­ list1­ enter all 100 lengths.
II. Stat ­ Calc ­ 1­Var Stats ­ enter
x is the mean 2
Discussion.
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