The numbers -5,7,-18,and 0 are examples of

How do I calculate 1/4-1/10 ?

Viktor [21]

Answer:

Hello there! I'm Ashlynn I'm always ready to help anyone in need of it!

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(1 / 4) - (1 / 10) = 0.15

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Calculate definition, to determine or ascertain by mathematical methods; compute: to calculate the velocity of light.

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“It makes a big difference in your life when you

stay positive.”

- Ellen DeGeneres

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 Have a great day!! 

  - Ashlynn

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8 0

3 years ago

the time t required to drive a certain distance varies inversely with the speed, r. if it takes 4 hours to drive the distance at

valina [46]

Hello,

Answer A

d :the distance in miles
t: the time in hours
v: the speed in miles/hours (vistesse)

d=v*t
==>d=40*4=160(mi)

d=55*x=160==>x=160/55=2.909090... (mi/(mi/h)=h)≈2.91(hours)

8 0

3 years ago

Find ten rational numbers between -2/3 and 2/3

Mama L [17]

Answer:

-2/3= -20/30

2/3 = 20/30

so rational numbers in between are

-19/30, -18/30, -17/30,........ -1/30, 0,+1/30,.............+17/30, +18/30, +19/30

so you can write as many as you like

8 0

2 years ago

A candidate for a US Representative seat from Indiana hires a polling firm to gauge her percentage of support among voters in he

UkoKoshka [18]

Answer:

a) The minimum sample size is 601.

b) The minimum sample size is 2401.

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of $\pi$ , and a confidence level of $1-\alpha$ , we have the following confidence interval of proportions.

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

In which

z is the zscore that has a pvalue of $1 - \frac{\alpha}{2}$ .

The margin of error is:

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

For this problem, we have that:

We dont know the true proportion, so we use $\pi = 0.5$ , which is when we are are going to need the largest sample size.

95% confidence level

So $\alpha = 0.05$ , z is the value of Z that has a pvalue of $1 - \frac{0.05}{2} = 0.975$ , so $Z = 1.96$ .

a. If a 95% confidence interval with a margin of error of no more than 0.04 is desired, give a close estimate of the minimum sample size that will guarantee that the desired margin of error is achieved. (Remember to round up any result, if necessary.)

This is n for which M = 0.04. So

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

$0.04 = 1.96\sqrt{\frac{0.5*0.5}{n}}$

$0.04\sqrt{n} = 1.96*0.5$

$\sqrt{n} = \frac{1.96*0.5}{0.04}$

$(\sqrt{n})^2 = (\frac{1.96*0.5}{0.04})^2$

$n = 600.25$

Rounding up

The minimum sample size is 601.

b. If a 95% confidence interval with a margin of error of no more than 0.02 is desired, give a close estimate of the minimum sample size necessary to achieve the desired margin of error.

Now we want n for which M = 0.02. So

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

$0.02 = 1.96\sqrt{\frac{0.5*0.5}{n}}$