All categories

2 years ago

How does the human body naturally create negative ions?

1 answer:

8 0

Negative ions are oxygen atoms charged with an extra electron. They are created in nature by the effects of water, air, sunlight and the Earth’s inherent radiation. We dont really create them in the human body.

You might be interested in

She serves the drinks at the interval. She serves 40 drinks in 20 minutes. What is the mean time she takes to serve 1 drink?

Alex Ar [27]

It takes her 2 minutes to serve 1 drink.

5 0

3 years ago

Read 2 more answers

A math tutor charges $30 per session each month plus a $5 scheduling fee. If jane pays a total of $215 in May for tutoring devic

wel

Answer:

it should be 6 not 100% sure though

Step-by-step explanation:

6 0

3 years ago

bianca is building a sandbox that will hold 4 cubic yards of sand. she wants it to be 18 inches deep and 2 yards wide. what will

tamaranim1 [39]

Length should be 2/5yd:

18inch*1yd/36inch=.5yd=> depth

volume= 2(length*width+lenght*depth+depth*width)

let l to be the length.

volume= 2(l*2+2(.5)+.5*2)

volume=5l+2

4=5l+2

2=5l

l=2/5

5 0

3 years ago

How do you graph a linear function to a line graph

anygoal [31]

Answer:

use point slope form

y=mx+b

8 0

3 years ago

There are 2,000 eligible voters in a precinct. A total of 500 voters are randomly selected and asked whether they plan to vote f

Ann [662]

Answer:

$0.7 - 2.58 \sqrt{\frac{0.7(1-0.7)}{500}}=0.647$

$0.7 + 2.58 \sqrt{\frac{0.7(1-0.7)}{500}}=0.753$

And the 99% confidence interval would be given (0.647;0.753).

So the correct answer would be:

a. 0.647 and 0.753

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The population proportion have the following distribution

$p \sim N(p,\sqrt{\frac{p(1-p)}{n}})$

Solution to the problem

The estimated population proportion for this case is:

$\hat p = \frac{350}{500}=0.7$

The confidence interval would be given by this formula

$\hat p \pm z_{\alpha/2} \sqrt{\frac{\hat p(1-\hat p)}{n}}$

For the 99% confidence interval the value of $\alpha=1-0.99=0.01$ and $\alpha/2=0.005$ , with that value we can find the quantile required for the interval in the normal standard distribution.

$z_{\alpha/2}=2.58$

And replacing into the confidence interval formula we got:

$0.7 - 2.58 \sqrt{\frac{0.7(1-0.7)}{500}}=0.647$

$0.7 + 2.58 \sqrt{\frac{0.7(1-0.7)}{500}}=0.753$

And the 99% confidence interval would be given (0.647;0.753).

So the correct answer would be:

a. 0.647 and 0.753

7 0

2 years ago