Please answer the question in the picture.
2 answers:
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Answer:
The 99% confidence interval of the population standard deviation is 1.7047 < σ < 7.485
Step-by-step explanation:
Confidence interval of standard deviation is given as follows;
s =
Where:
= Sample mean
s = Sample standard deviation
n = Sample size = 7
χ = Chi squared value at the given confidence level
= ∑x/n = (62 + 58 + 58 + 56 + 60 +53 + 58)/7 = 57.857
The sample standard deviation s = = 2.854
The test statistic, derived through computation, = ±3.707
Which gives;
1.7047 < σ < 7.485
The 99% confidence interval of the population standard deviation = 1.7047 < σ < 7.485.
Answer:
Vertex is (-4, -18)
Step-by-step explanation:
f(x) =
Let (h, k) be the vertex
An easy way to find h is to use the formula h = -b/2a
In your case where f(x) = a = 2 and b = 8
So, h = -8/2(1) = -8/2 = -4
Substitue -4 in for x to find k
k = () + 8(-4) - 2
= (16) - 32 - 2
= 16 - 32 - 2
= -18
Vertex is (-4, -18)
Note: Another way to find the vertex is to complete the square, but this can really be difficult in some cases