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Kay [80]
3 years ago
15

A spherical weather balloon is being inflated. The radius of the balloon is increasing at the rate of 9 cm/s. Express the surfac

e area of the balloon as a function of time t (in seconds). (Let S(0) = 0.)
Mathematics
1 answer:
Zolol [24]3 years ago
8 0
Since a sphere's surface area is 4πr², we then need to find r as a function of time t, which is 9t (since it increases by 9 every second)+0 (the initial value)=9t. Plugging it in, we get 4π(9t)²=4π*36t²=144πt²
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Answer:

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Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".  

The margin of error is the range of values below and above the sample statistic in a confidence interval.  

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X=12 represent the number of masks that had lenses pop out at 250°

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p represent the population proportion of masks that  had lenses pop out at 250°

Confidence =0.9 or 90%

\alpha=0.1 represent the significance level

Confidence interval

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So the critical value would be on this case z_{\alpha}=1.28 and we can use the following excel code to find it: "=NORM.INV(1-0.1,0,1)"

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An independent variable is the variable that can be changed whilst the dependant variable cannot be changed to keep a fair test ✅
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