Find the 8th term of the geometric sequence. An=-2.5•4^n-1
1 answer:
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Answer: a) -0.2252, b) 0.8219
Step-by-step explanation:
Since we have given that
Sample size n = 100
Probability that candies are blue = p= 0.26
Probability that company claims that it is blue candy = P = 0.27
So, Q = 1-P= 1-0.27 = 0.73
So, Null hypothesis :
Alternate hypothesis :
So, the test statistic would be
Since α = 0.05
So, critical value of z = 1.96
p-value = P(Z>Z(calculated)
Using the excel function , we get that
Hence, a) -0.2252, b) 0.8219
Answer:
f(r) = (x -1)(x -4+√7)(x -4-√7)
Step-by-step explanation:
The signs of the terms are + - + -. There are 3 changes in sign, so Descartes' rule of signs tells you there are 3 or 1 positive real roots.
The rational roots, if any, will be factors of 9, the constant term. The sum of coefficients is 1 -9 +17 -9 = 0, so you know that r=1 is one solution to f(r) = 0. That means (r -1) is a factor of the function.
Using polynomial long division, synthetic division (2nd attachment), or other means, you can find the remaining quadratic factor to be r^2 -8r +9. The roots of this can be found by various means, including completing the square:
r^2 -8r +9 = (r^2 -8r +16) +9 -16 = (r -4)^2 -7
This is zero when ...
(r -4)^2 = 7
r -4 = ±√7
r = 4±√7
Now, we know the zeros are {1, 4+√7, 4-√7), so we can write the linear factorization as ...
f(r) = (r -1)(r -4 -√7)(r -4 +√7)
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<em>Comment on the graph</em>
I like to find the roots of higher-degree polynomials using a graphing calculator. The red curve is the cubic. Its only rational root is r=1. By dividing the function by the known factor, we have a quadratic. The graphing calculator shows its vertex, so we know immediately what the vertex form of the quadratic factor is. The linear factors are easily found from that, as we show above. (This is the "other means" we used to find the quadratic roots.)
