Answer:
it measures spread around the mean. Because of its close links with the mean, standard deviation can be greatly affected if the mean gives a poor measure of central tendency. Standard deviation is also influenced by outliers one value could contribute largely to the results of the standard deviation.
Step-by-step explanation:

Thickness of the book is ~
Refer to the attachment for solution ~
Answer:
x(3y - 1) and (2a - 3)(2a + 3)
Step-by-step explanation:
(1)
3xy - x ← factor out x from each term
= x(3y - 1)
(2)
4a² - 9 ← is a difference of squares and factors in general as
a² - b² = (a - b)(a + b) , then
4a² - 9
= (2a)² - 3²
= (2a - 3)(2a + 3)
Answer:
241/20
Step-by-step explanation:
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