0.85 is equal to 6/7 because you divide six by seven....Hope this helped.
Answer:
a

b

Step-by-step explanation:
From the question we are told that
The data is 87 91 86 82 72 91 60 77 80 79 83 96
Generally the point estimate for the mean is mathematically represented as

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Generally the point estimate for the standard deviation is mathematically represented as

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hope this helped
mark brainliest :)
The complex solution of a quadratic equation are (- 2 + i ) and
(- 2 - i ).
What is Quadratic equation?
An algebraic equation of the second degree is called a quadratic equation.
Given that;
A quadratic equation is;
3x² = -12x - 15
Now, The equation is written as;
3x² + 12x + 15 = 0
Take 3 common, we get;
3 (x² + 4x + 5) = 0
x² + 4x + 5 = 0
Factorize the equation by using Sridharacharya Formula;
x = - 4 ± √4² - 4*1*5 / 2*1
x = -4 ± √16 - 20 / 2
x = - 4 ± √-4 / 2
Since, √-1 = i
x = -4 ± 2i / 2
x = - 2 ± i
It gives two values of x as;
x = - 2 + i
And, x = - 2 - i
Hence, The complex solution of a quadratic equation are (- 2 + i ) and
(- 2 - i ).
Learn more about the quadratic equation visit:
brainly.com/question/24334139
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