Answer:
3. Standard deviation is the square root of the variance.
4. Standard deviation is useful because it has the same units as the underlying data.
Step-by-step explanation:
3. In statistics, the dispersion in a given data with respect to its mean distribution can be determined or measured by standard deviation and variance. The standard deviation of a distribution can also be determined as the square root of variance.
4. Standard deviation is measured in the same units as that of the original data. Thus it has the same units as the underlying data.
Answer:
The number of ways is equal to 
Step-by-step explanation:
The multiplication principle states that If a first experiment can happen in n1 ways, then a second experiment can happen in n2 ways ... and finally a i-experiment can happen in ni ways therefore the total ways in which the whole experiment can occur are
n1 x n2 x ... x ni
Also, given n-elements in which we want to put them in a row, the total ways to do this are n! that is n-factorial.
For example : We want to put 4 different objects in a row.
The total ways to do this are 
ways.
Using the multiplication principle and the n-factorial number :
The number of ways to put all 40 in a row for a picture, with all 12 sophomores on the left,all 8 juniors in the middle, and all 20 seniors on the right are : The total ways to put all 12 sophomores in a row multiply by the ways to put the 8 juniors in a row and finally multiply by the total ways to put all 20 senior in a row ⇒
1 file + 3 pens = $32.85 --------------- (1)
2 files + 8 pens = $83.50 ----------------(2)
(1) x 2 :
2 files + 6 pens = $65.70 ----------------(1a)
(2) - (1a) :
2 pens = $17.80
1 pen = $8.90
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Answer: One pen costs $8.90.
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12 problems = 30 minutes
24 problems = 60 minutes
36 problems= 90 minutes
48 problems = 120 minutes
60 problems = 150 minutes
Mary can respond 60 problems in 2 hours and 30 minutes/ 2 hours and half/ 150 minutes.
Hope this helps xx
Answer
402 meters ÷ 18 seconds
Step-by-step explanation:
