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3 years ago

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A water balloon is thrown out of a window 96 feet above the ground. The balloon is traveling downward at 16 feet per second init

ially. If h is the balloon’s height in feet after t seconds, then h = -16t 2 -16t + 96, It will take the balloon blank seconds to hit the ground.

2 answers:

victus00 [196]3 years ago

6 0

It takes the water ballon 2 seconds to hit the ground

Tema [17]3 years ago

5 0

-16t²-16t+96 = 0. use quadratic equation the roots are x= -3, and 2. 2 is the only answer that makes sense. So it takes 2 seconds

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Bogdan [553]

Answer:

a) 6.68% of heights less than 150 centimeters

b) 58.65% of heights between 160 centimeters and 180 centimeters

Step-by-step explanation:

When the distribution is normal, we use the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

In this question, we have that:

$\mu = 162, \sigma = 8$

a) The percentage of heights less than 150 centimeters

We have to find the pvalue of Z when X = 150. So

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{150 - 162}{8}$

$Z = -1.5$

$Z = -1.5$ has a pvalue of 0.0668

6.68% of heights less than 150 centimeters

b) The percentage of heights between 160 centimeters and 180 centimeters

We have to find the pvalue of Z when X = 180 subtracted by the pvalue of Z when X = 160.

X = 180

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{180 - 162}{8}$

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X = 160

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{160 - 162}{8}$

$Z = -0.25$

$Z = -0.25$ has a pvalue of 0.4013

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3 years ago

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alexandr1967 [171]

Answer:

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Step-by-step explanation:

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3 years ago

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Answer:

The 95% confidence interval estimate for the true proportion of adults residents of this city who have cell phones is (0.81, 0.874).

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of $\pi$ , and a confidence level of $1-\alpha$ , we have the following confidence interval of proportions.

$\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}$

In which

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Answer:

Step-by-step explanation:

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