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3 years ago

Do the functions have the same concavity? f(x)=2x^2-10x-30

Mathematics

2 answers:

Talja [164]3 years ago

6 0

Answer:

Step-by-step explanation:

love history [14]3 years ago

5 0

Answer:

Use the inflection points to set up intervals. Substitute a value into each interval to find where the curve is concave up or down.

The graph is concave up

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Families USA, a monthly magazine that discusses issues related to health and health costs, surveyed 20 of its subscribers. It fo

Harman [31]

Answer:

(a) The 90 percent confidence interval for the population mean yearly premium is ($10,974.53, $10983.47).

(b) The sample size required is 107.

Step-by-step explanation:

(a)

The (1 - <em>α</em>)% confidence interval for population mean is:

$CI=\bar x\pm t_{\alpha/2, (n-1)}\times \frac{s}{\sqrt{n}}$

Given:

$\bar x=\$10,979\\s=\$1000\\n=20$

Compute the critical value of <em>t</em> for 90% confidence level as follows:

$t_{\alpha/2, (n-1)}=t_{0.10/2, (20-1)}=t_{0.05, 19}=1.729$

*Use a <em>t-</em>table.

Compute the 90% confidence interval for population mean as follows:

$CI=\bar x\pm t_{\alpha/2, (n-1)}\times \frac{s}{\sqrt{n}}$

$=10979\pm 1.729\times \frac{1000}{\sqrt{20}}\\=10979\pm4.47\\ =(10974.53, 10983.47)$

Thus, the 90 percent confidence interval for the population mean yearly premium is ($10,974.53, $10983.47).

(b)

The margin of error is provided as:

MOE = $250

The confidence level is, 99%.

The critical value of <em>z</em> for 99% confidence level is:

$z_{\alpha/2}=z_{0.01/2}=z_{0.005}=2.58$

Compute the sample size as follows:

$MOE= z_{\alpha/2}\times \frac{s}{\sqrt{n}}$

$n=[\frac{z_{\alpha/2}\times s}{MOE} ]^{2}$

$=[\frac{2.58\times 1000}{250}]^{2}$

$=106.5024\\\approx107$

Thus, the sample size required is 107.

4 0

3 years ago

Three equivalent ratios to 10/12 simplistic form

11Alexandr11 [23.1K]

<h2><u>Answer:</u></h2><h3>Equivalent Ratios:</h3>

20/24, 30/36 & 40/48

<h3>Simplest Form:</h3>

5/6

<h2><u>Step-by-step explanation:</u></h2><h3>Equivalent Ratios:</h3>

10 × 2 / 12 × 2 = 20/24

10 × 3 / 12 × 3 = 30/36

10 × 4 / 12 × 4 = 40/48

<h3>Simplest Form:</h3>

10 ÷ 2/ 12 ÷ 2 = 5/6

8 0

3 years ago

What is the value of a?

Sindrei [870]

Answer:

a=2

Step-by-step explanation:

Firstly, in order to simplify the expression, we should aim to combine the two terms given. In order to do this, both must have the same denominator. We can give them the same denominator by multiplying the second term $-\frac{2}{x+2}$ by $\frac{x+2}{x+2}$ . This way the fraction value remains the same but now has the same denominator as the first term:

$-\frac{2}{x+2} *\frac{x+2}{x+2} \\\\=\frac{(-2)(x+2)}{(x+2)(x+2)} \\\\=\frac{-2x-4}{(x+2)^{2}}$

From here we can now combine the two terms:

$\frac{2x+6}{(x+2)^{2}} +\frac{-2x-4}{(x+2)^{2}} \\\\= \frac{(2x+6)+(-2x-4)}{(x+2)^{2}} \\\\\\=\frac{2x+6-2x-4}{(x+2)^{2}}\\\\= \frac{2}{(x+2)^{2}}$

Therefore, a = 2.

Hope this helped!

6 0

2 years ago

If you have 50 red bead 50 blue beads 50 green beads what I'd the probability that will be blue

makkiz [27]

Add all the beads together and put it over the number of blue beads.
so since there are 150 beads, the denominator is 150. and the amount of blue beads is 50 so that's the numerator.
50/150 now simplify, divide the numerator and denominator by 50 that equals
1/3
so the probability of getting a blue bead is 1/3
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6 0

4 years ago

Read 2 more answers

URGET!!! IM TAKING A TEST. DUE TODAY

Novay_Z [31]

Answer:

15x $\geq$ 345

x = number of hours she works

Step-by-step explanation:

First: find the inequality symbol

If she wants to earn at least 345, she wants to make 345 or more

that means you use the greater than or equal symbol ( $\geq$ )

Next, if she makes 15 dollars an hour, x has to be the number of hours she works. The left side of the inequality would be $15* number of hours, or 15x

Thus, your inequality would be 15x $\geq$ 345

7 0

3 years ago