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2 years ago

9. The radius of a circle is 6.

Mathematics

1 answer:

Arlecino [84]2 years ago

7 0

Answer:

12,5.196

Step-by-step explanation:

given that the radius of a circle is 6.

We have any tangent drawn from outside point there will be two tangents of equal length and also the line joining point of intersection of tangent with centre of circle will bisect the angle between the tangents.

When angle between the two tangents is 60, we have the right triangle formed by radius, one tangent, and line joining point of intersection of tangent with centre of circle with angles 30,60 and 90

Hence the hypotenuse = length of line segment of tangent = 2 (radius) = 12

Part 2:

When angle between tangents is 120, we have 60,30,90 right triangle and hence length of tangent = radius * sin 60

= $6*\frac{\sqrt{3} }{2} \\=5.196$

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It is the absolute value

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3 years ago

A clinical trial was conducted to test the effectiveness of the drug zopiclone for treating insomnia in older subjects. Before t

aleksklad [387]

Answer:

We cannot say that the mean wake time are different before and after the treatment, with 98% certainty. So the zopiclone doesn't appear to be effective.

Step-by-step explanation:

The goal of this analysis is to determine if the mean wake time before the treatment is statistically significant. The question informed us the mean wake time before and after the treatment, the number of subjects and the standard deviation of the sample after treatment. So using the formula, we can calculate the confidence interval as following:

$IC[\mu ; 98\%] = \overline{y} \pm t_{0.99,n-1}\sqrt{\frac{Var(y)}{n}}$

Knowing that $t_{0.99,15} = 2.602$ :

$IC[\mu ; 98\%] = 98.9 \pm 2.602\frac{42.3}{4} \Rightarrow 98.9 \pm 27.516$

$IC[\mu ; 98\%] = [71.387 ; 126,416]$

Note that $102.8 \in [71.384 ; 126.416]$ so we cannot say, with 98% confidence, that the mean wake time before treatment is different than the mean wake time after treatment. So the zopiclone doesn't appear to be effective.

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2 years ago

The box which measures 70cm X 36cm X 12cm is to be covered by a canvas. How many meters of canvas of width 80cm would be require

grigory [225]

Answer:

142.2 meters.

Step-by-step explanation:

We have been given that a box measures 70 cm X 36 cm X 12 cm is to be covered by a canvas.

Let us find total surface area of box using surface area formula of cuboid.

$\text{Total surface area of cuboid}=2(lb+bh+hl)$ , where,

$l$ = Length of cuboid,

$b$ = Breadth of cuboid,

$w$ = Width of cuboid.

$\text{Total surface area of box}=2(70\cdot36+36\cdot 12+12\cdot 70)$

$\text{Total surface area of box}=2(2520+432+840)$

$\text{Total surface area of box}=2(3792)$

$\text{Total surface area of box}=7584$

Therefore, the total surface area of box will be 7584 square cm.

To find the length of canvas that will cover 150 boxes, we will divide total surface area of 150 such boxes by width of canvass as total surface area of canvas will also be the same.

$\text{Width of canvas* Length of canvass}=\text{Total surface area of 150 boxes}$