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2 years ago

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Tracy has a cell phone plan that provides 250 free minutes each month for a flat rate of 29$. For any minutes over 250 tracy us

charged 0.35$ per minute. Which of the following picewise functions represents charges based on tracy’s cell phone plane?

1 answer:

iVinArrow [24]2 years ago

7 0

Answer:

Since Tracy is charged $29 for 250 free minutes so:

For x ≤ 250, f(x) = $29

tracy is charged an extra $0.35 per minute for calls over 250 minutes, so:

For x ≥ 250, f(x) = 29 + 0.35(x - 250)

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A politician estimates that 61% of his constituents will vote for him in the coming election. How many constituents are required

Katyanochek1 [597]

Using the z-distribution, as we are working with a proportion, it is found that 1016 constituents are required.

<h3>What is a confidence interval of proportions?</h3>

A confidence interval of proportions is given by:

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

In which:

$\pi$ is the sample proportion.

z is the critical value.

n is the sample size.

The margin of error is given by:

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

In this problem, we have a 95% confidence level, hence $\alpha = 0.95$ , z is the value of Z that has a p-value of $\frac{1+0.95}{2} = 0.975$ , so the critical value is z = 1.96.

The estimate is of $\pi = 0.61$ , while the margin of error is of M = 0.03, hence solving for n we find the minimum sample size.

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

$0.03 = 1.96\sqrt{\frac{0.61(0.39)}{n}}$

$0.03\sqrt{n} = 1.96\sqrt{0.61(0.39)}$

$\sqrt{n} = \frac{1.96\sqrt{0.61(0.39)}}{0.03}$

$(\sqrt{n})^2 = \left(\frac{1.96\sqrt{0.61(0.39)}}{0.03}\right)^2$

$n = 1015.5$

Rounding up, 1016 constituents are required.

More can be learned about the z-distribution at brainly.com/question/25890103

8 0

1 year ago

The approximate number of bicycles in the United States in the year 2007 was 14,000,000. How can this number be expressed in sci

elena-s [515]

Answer:

$1.4*10^7$

Step-by-step explanation:

we have

$14,000,000$

Remember that

$14,000,000=1.4(10,000,000)$

and

$10,000,000=1*10^7=10^7$

substitute

$14,000,000=1.4*10^7$

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3 years ago

One package of blueberries costs $3.<br>How many packages of blueberries can<br>you buy with $12?

Pachacha [2.7K]

Answer:

4

Step-by-step explanation:

Because 3×4=12

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3 years ago

Read 2 more answers

Determine whether the ordered pair (1, 1) is a solution of the inequality. y ≤ -3x+1

solong [7]

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Answer: $\textsf{(1, 1) is NOT a solution of the inequality}$

-------------------------------------------------------------------------------------------------------------

Given: $y \le-3x + 1$

Find: $\textsf{Determine if (1, 1) is a solution of the inequality}$

Solution: In order to determine if (1, 1) is a solution we need to plug in 1 for the x values and 1 for the y values and see if the equation evaluated to true.

<u>Plug in the values</u>

$y \le-3x + 1$

$1 \le-3(1) + 1$

<u>Simplify</u>

$1 \le-3 + 1$

$1 \le-2$

As we can see the expression states that 1 is less than or equal to -2 which is false therefore (1, 1) is NOT a solution of the inequality.

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1 year ago

What is the range of f(x)=1/2^x

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Downloaded Photomath it’s going to help you a lot

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