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4 years ago

X^2+6x+4 equivalent

Mathematics

1 answer:

LenaWriter [7]4 years ago

3 0

Answer:

x = ± √ 13 + 3

Step-by-step explanation:

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10.

Kay [80]

Answer:

$\frac{(82)(2.4)^2}{104.139} \leq \sigma^2 \leq \frac{(82)(2.4)^2}{62.132}$

$4.535 \leq \sigma^2 \leq 7.602$

Now we just take square root on both sides of the interval and we got:

$2.2 \leq \sigma \leq 2.8$

And the best option would be:

A. 2.2 < σ < 2.8

Step-by-step explanation:

Information provided

$\bar X=32.1$ represent the sample mean

$\mu$ population mean

s=2.4 represent the sample standard deviation

n=83 represent the sample size

Confidence interval

The confidence interval for the population variance is given by the following formula:

$\frac{(n-1)s^2}{\chi^2_{\alpha/2}} \leq \sigma^2 \leq \frac{(n-1)s^2}{\chi^2_{1-\alpha/2}}$

The degrees of freedom are given by:

$df=n-1=83-1=82$

The Confidence is given by 0.90 or 90%, the value of $\alpha=0.1$ and $\alpha/2 =0.05$ , the critical values for this case are:

$\chi^2_{\alpha/2}=62.132$

$\chi^2_{1- \alpha/2}=104.139$

And replacing into the formula for the interval we got:

$\frac{(82)(2.4)^2}{104.139} \leq \sigma^2 \leq \frac{(82)(2.4)^2}{62.132}$

$4.535 \leq \sigma^2 \leq 7.602$

Now we just take square root on both sides of the interval and we got:

$2.2 \leq \sigma \leq 2.8$

And the best option would be:

A. 2.2 < σ < 2.8

3 0

3 years ago

On a factory floor, 30 out of every 140 toy robots is defective. What percent is defective?

yaroslaw [1]

Answer:

$21.43\%$

Step-by-step explanation:

we know that

To find out the percent of robots which are defective, divided the number of defective robots by the total number of robots and multiply the result by 100

Let

x ----> the number of defective robots

y ----> the total number of robots

p ---> percentage of robots which are defective

$p=\frac{x}{y} (100)$

we have

$x=30\\y=140$

substitute

$p=\frac{30}{140}(100)$

$p=21.43\%$

5 0

4 years ago

You are playing a card game with friends. at one point. you double your score. in the next hand you lose 75 points. you end up w

Gnoma [55]

Answer:

i) x points; ii) 2x - 75 = -25; iii) x = 25

Step-by-step explanation:

i) Starting points

Let's say you had x points before doubling your score.

(ii) The equation

After doubling score: 2x points

After losing 75 points: (2x - 75) points

At end of game: -25 points

The equation is

2x - 75 = -25

iii) Solution to equation

2x - 75 = -25 Add 75 to each side

2x = 50 Divide each side by 2

x = 25

3 0

4 years ago

What is the answer. Evalute (2/3)2. Thank you

polet [3.4K]

Answer:

4/3

Step-by-step explanation:

5 0

3 years ago

Read 2 more answers

Aisha had a of ribbon. She used 15% of the ribbon to decorate cards and had 17 feet of ribbon left. She then used 20% of the rem

Tcecarenko [31]

Answer:

The total amount of ribbon she had was 35 feet of ribbon.

Step-by-step explanation:

I hope this is one of the answers and I hope this helps you. Stay safe:)

3 0

3 years ago

Read 2 more answers