These are the values:
18.2 17.6
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18.9 18.6
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20 19.7 19.8 19.6
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21.4 20.6 21
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21.9 22.1 22.2 22.2 21.6
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23.1 22.6 23.2 23 22.9 23.2 23.2 23 22.5 22.5
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23.8 24.1 23.8 23.6 24.3 23.7 24 24.2 24.4 23.8 23.5
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24.7 24.9 25 25.4 25.1 25.3 25.3 25.2 25.2 24.7 24.6 24.5 24.5
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25.6 26 25.6 25.6 25.6 25.7 25.6 26.3 26.3 26.2 26 25.9 26.2 26
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27 27.2 27 27.2 26.7 27 26.6 27.3 26.8 26.6 26.9 27 26.5
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28.2 27.7 28.1 27.9 27.6 27.7 28.1 28.2 27.5
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28.6 29.1 28.7 29.1
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30.3 29.6 29.7 29.5
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30.9 31 31 30.5
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32.3 31.6
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These are the groups:
- 17.5 - 18.5
- 18.5 - 19.5
- 19.5 - 20.5
- 20.5 - 21.5
- 21.5 - 22.5
- 22.5 - 23.5
- 23.5 - 24.5
- 24.5 - 25.5
- 25.5 - 26.5
- 26.5 - 27.5
- 27.5 - 28.5
- 28.5 - 29.5
- 29.5 - 30.5
- 30.5 - 31.5
- 31.5 - 32.5
I'm supposed to calculate the standard deviation and the expected value ... How is it different comparing to having only 15 values and not divided them into groups? If I only have 15 values, I know how to calculate the stand.deviation and the exp.value. I use the formulas that are well-known:
Exp.value: ............(1/n)*Sum(xi)..................where xi = all the 15 values <br>
Stand.deviation: ...(1/(n-1))*Sum( xi - u)^2...where xi = all the 15 values and u = exp.value
n-1
probably should be replaced byn
.) (2) You ask about the difference between treating these data as 100 values and 15 values. Why don't you just compute the formulas you think should apply and compare what you get? $\endgroup$