Answer:
see explanation
Step-by-step explanation:
The sum of the 3 angles in a triangle = 180°
sum the 3 angles and equate to 180
5x + 7 + 4x + 2 + 90 = 180 , that is
9x + 99 = 180 ( subtract 99 from both sides )
9x = 81 ( divide both sides by 9 )
x = 9
Then
∠ ACB = 4x + 2 = 4(9) + 2 = 36 + 2 = 38°
∠ BAC = 5x + 7 = 5(9) + 7 = 45 + 7 = 52°
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Since the triangles are congruent then corresponding angles are congruent , so
∠ B = ∠ E
6x + 10 = 70 ( subtract 10 from both sides )
6x = 60 ( divide both sides by 6 )
x = 10
Answer:
2/3 hours
Step-by-step explanation:
40 minutes = 40/60 = 2/3 hours
Answer:
Yes
Step-by-step explanation:
First, suppose that nothing has changed, and possibility p is still 0.56. It's our null hypothesis. Now, we've got Bernoulli distribution, but 30 is big enough to consider Gaussian distribution instead.
It has mean μ= np = 30×0.56=16.8
standard deviation s = √npq
sqrt(30×0.56×(1-0.56)) = 2.71
So 21 is (21-16.8)/2.71 = 1.5494 standard deviations above the mean. So the level increased with a ˜ 0.005 level of significance, and there is sufficient evidence.
