Answer:
<h2>6.63</h2>
Step-by-step explanation:
Standard error of the mean is expressed as shown below.
SE = S/√n where;
S is the standard deviation
n is the sample suze
Given parameters
Standard deviation = $23.90
sample size = 13
Required
Standard error of the mean for this distribution.
Substituting the given value into the formula we have;
SE = 23.90/√13
SE = 23.90/3.6056
SE = 6.6286
<em>Hence the approximate standard error of the mean for this sample is 6.63</em>
Answer:
Step-by-step explanation:
(B). - 28.7
Answer:
(3x + 11y)^2
Step-by-step explanation:
The polynomial is a perfect square trinomial, because:
1) √ [9x^2] = 3x
2) √121y^2] = 11y
3) 66xy = 2 *(3x)(11y)
Then it is factored as a square binomial, being the factored expression:
[ 3x + 11y]^2
Now you can verify working backwar, i.e expanding the parenthesis.
Remember that the expansion of a square binomial is:
- square of the first term => (3x)^2 = 9x^2
- double product of first term times second term =>2 (3x)(11y) = 66xy
- square of the second term => (11y)^2 = 121y^2
=> [3x + 11y]^2 = 9x^2 + 66xy + 121y^2, which is the original polynomial.