Question

i need help with 3-8 anyone....i will give medals....

Answer 1

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

Answer 2

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

Answer 3

@Concentrationalizing

Answer 4

@jabez177

Answer 5

@Awolflover1

Answer 6

@sleepyjess

Answer 7

@ganeshie8

Answer 8

Using your values we get (see attached):

Answer 9

You'll see how we compute mean and standard deviation in the attached above:

Mean \( \bar{x}=81.72\)
Standard deviation \(\sigma = 10.4\)

Answer 10

You can drill down into each cell in the spreadsheet to see the formula I used.

Does this make sense?

Answer 11

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.

Answer 12

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