Saylilbaby one year ago i need help with 3-8 anyone....i will give medals....

1. saylilbaby

2. ybarrap

In order to complete this exercise, you'll need to count the number of dots for each bin: I'll start 60 - 1 61 - 1 62 - 0 63 - 1 ... Finish the rest and we'll continue

3. saylilbaby

60-1 61-1 62-0 63-1 64-0 65-1 66-0 67-0 68-3 69-2 70-2 71-0 72-1 73-0 74-1 75-0 76-3 77-0 78-1 79-1 80-4 81-0 82-4 83-0 84-1 85-2 86-3 87-1 88-1 89-1 90-5 91-0 92-4 93-0 94-0 95-3 96-0 97-0 98-1 99-1 100-1 @ybarrap

4. saylilbaby

@Concentrationalizing

5. saylilbaby

@jabez177

6. saylilbaby

@Awolflover1

7. saylilbaby

@sleepyjess

8. saylilbaby

@ganeshie8

9. ybarrap

Using your values we get (see attached):

10. ybarrap

You'll see how we compute mean and standard deviation in the attached above: Mean $$\bar{x}=81.72$$ Standard deviation $$\sigma = 10.4$$

11. ybarrap

You can drill down into each cell in the spreadsheet to see the formula I used. Does this make sense?

12. ybarrap

We used the following definition for mean and standard deviation: $$\operatorname{E}[X] = x_1p_1 + x_2p_2 + \dotsb + x_kp_k \;\\ \operatorname{Var}(X) = \sum_{i=1}^n p_i\cdot(x_i - \mu)^2 = \sum_{i=1}^n (p_i\cdot x_i^2) - \mu^2\\ \sigma = \sqrt{Var(X)}$$ Where $$x_i$$ are the bin values, 60, 61, etc...and $$p_i$$ are their probabilities.

13. ybarrap

And $$\bar{x}=E[X]$$