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3 years ago

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Claim: Most adults would not erase all of their personal information online if they could. A software firm survey of 677 random

ly selected adults showed that 49.9% of them would erase all of their personal information online if they could. Make a subjective estimate to decide whether the results are significantly low or significantly high, then state a conclusion about the original claim. Find the value of the test statistic.

1 answer:

Alika [10]3 years ago

3 0

Answer: The value of test statistic is -0.052.

Step-by-step explanation:

Since we have given that

n = 677

and

$\bar {p}=0.499$

Claim that Most of the adults erase all of their personal details online.

p = 0.5

q = 1-0.5 = 0.5

So, the test statistic would be

$z=\dfrac{\bar{p}-p}{\sqrt{\dfrac{pq}{n}}}\\\\z=\dfrac{0.499-0.5}{\sqrt{\dfrac{0.5\times 0.5}{677}}}\\\\z=\dfrac{-0.001}{0.0192}\\\\z=-0.052$

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Answer:

part 1) 0.78 seconds

part 2) 1.74 seconds

Step-by-step explanation:

step 1

At about what time did the ball reach the maximum?

Let

h ----> the height of a ball in feet

t ---> the time in seconds

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This is a vertical parabola open downward (the leading coefficient is negative)

The vertex represent a maximum

so

The x-coordinate of the vertex represent the time when the ball reach the maximum

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Convert the equation in vertex form

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$h(t)=-16(t^{2}-\frac{25}{16}t)+5$

Complete the square

$h(t)=-16(t^{2}-\frac{25}{16}t+\frac{625}{1,024})+5+\frac{625}{64}$

$h(t)=-16(t^{2}-\frac{25}{16}t+\frac{625}{1,024})+\frac{945}{64}\\h(t)=-16(t^{2}-\frac{25}{16}t+\frac{625}{1,024})+\frac{945}{64}$

Rewrite as perfect squares

$h(t)=-16(t-\frac{25}{32})^{2}+\frac{945}{64}$

The vertex is the point $(\frac{25}{32},\frac{945}{64})$

therefore

The time when the ball reach the maximum is 25/32 sec or 0.78 sec

step 2

At about what time did the ball reach the minimum?

we know that

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For h=0

$0=-16(t-\frac{25}{32})^{2}+\frac{945}{64}$

$16(t-\frac{25}{32})^{2}=\frac{945}{64}$

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Answer:

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Step-by-step explanation:

We are interested in determining whether or not the proportion of the student who experience anxiety during the exam is significantly more than 80%.

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Answer:

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Step-by-step explanation:

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Answer:

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