Answer:
Confidence interval: (21.9, 32.9).
Step-by-step explanation:
We have the standard deviation for the sample, which means that the t-distribution is used to solve this question.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 26 - 1 = 25
98% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 25 degrees of freedom(y-axis) and a confidence level of 
. So we have T = 2.485
The margin of error is:
In which s is the standard deviation of the sample and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 27.4 - 5.5 = 21.9 hours
The upper end of the interval is the sample mean added to M. So it is 27.4 + 5.5 = 32.9 hours
Confidence interval: (21.9, 32.9).
Difference of 2 perfect squares
a^2-b^2=(a-b)(a+b)
recognize that
(2x+1)(2x-1)
(a+b)(a-b)
therefor
product is
(2x)^2-(1)^2=
4x^2-1
Answer:
The value is 
Step-by-step explanation:
From the question we are told that
And that
So the number of sand grain that is in 
is mathematically evaluated as
=>
The other endpoint would have to be (-5,2), going off the definition of a midpoint. Since 3 is for units to the right of -1, that would mean that the other end point would have to be 4 units to the left, which is -5.
If the roots of the equation f(x)=0 are -4,-1, 2 and 5, then binomials (x+4), (x+1), (x-2) and (x-5) are factors of needed polynomial.
Thus, the polynomial will have form
where a is real coefficient (positive or negative). This polynomial has degree 4 as needed.
The form of the graph depends on the sign of coefficient a. Attached diagrams show two different cases of possible forms of graphs (first one for positive coefficient a, second one for negative coefficient a).
