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4 years ago

X^2 + y^2=40 and y=x-4 solve this simultaneous equation

1 answer:

3 0

Write x-4 instead of y.
x²+(x-4)²=40
x²+x²-8x+16=40
2x²-8x-24=0
x²-4x-12=0
(x-6)(x+2)=0
x=6 or x=-2

for x=6, y=6-4 = 2
for x=-2, y=-2-4 = -6

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A sample of 11 students using a Ti-89 calculator averaged 31.5 items identified, with a standard deviation of 8.35. A sample of

lina2011 [118]

Answer:

We reject H₀, with CI = 90 % we can conclude that the mean numbers of times identified with Ti-84 does not exceed that of the Ti-89 by more than 1,80

Step-by-step explanation:

Ti-89 Calculator

Sample mean x = 31,5

Sample standard deviation s₂ = 8,35

Sample size n₂ = 11

Ti-84 Calculator

Sample mean y = 46,2

Sample standard deviation s₁ = 9,99

Sample size n₁ = 12

t(s) = ( y - x - d ) / √s₁²/n₁ + s₂²/n₂

t(s) = 12,9 / √(99,8/12) + (69,72/11)

t(s) = 12,9 / √8,32 + 6,34

t(s) = 12,9 / 3,83

t(s) = 3,37

Test Hypothesis

Null Hypothesis H₀ y - x > 1,80

Altenative Hypothesis Hₐ y - x ≤ 1,80

We have a t(s) = 3,37

We need to compare with t(c) critical value for

t(c) α; n₁ +n₂-2 df = 12 +11 -2 df = 21

If we choose CI = 95 % then α = 5 % α = 0,05

From t-student table

t(c) = 1,72

t(s) = 3,37

t(s) >t(c)

t(s) is in the rejection region therefore we accept Hₐ with CI = 95 %

8 0

3 years ago

What is the volume of a rectangular prism with the following dimensions

andriy [413]

Answer: 250ft3

Step-by-step explanation:

v=l*w*H

v= 10*5 * 5

v=250

7 0

4 years ago

Read 2 more answers

What divided by 8 equals 2?

Fed [463]

Eight divided by 4 equals 2

4 0

3 years ago

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What are parallel lines

tankabanditka [31]

Answer:

Parallel lines are lines <u>in the same plane</u> that do not intersect, like lines on notebook paper.

The "in the same plane" requirement is important! Take a look at the attached image. Lines AD and DC don't intersect, but they are <u>not</u> in the same plane (face of the rectangular solid). We don't call those parallel, we call them skew lines.