Solve the following equation -2x + 4 = 2 (4x - 3) -3 (-8 + 4x)<br> a.7<br> b.2<br> c.-7<br> d.3

The radius of a wheel is 21m.how much distance will it covers when it rotates 5 times?

mrs_skeptik [129]

Answer:

Distance = 660 meters

Step-by-step explanation:

Given the following data;

Radius, r = 21 m

Number of revolutions = 5 times

To find the distance covered;

The distance covered in one revolution is given by the circumference of a circle.

Mathematically, circumfeence of a circle is equal to;

C = 2πr

Substituting into the formula, we have;

C = 2 * 22/7 * 21

C = 44 * 3

C = 132 meters

Next, we find the distance covered;

Distance = Circumference * Number of revolutions

Distance = 132 * 5

Distance = 660 meters

8 0

2 years ago

Please help I need this question ASAP please help I am begging

MaRussiya [10]

bill nye is in fact the science guy

3 0

2 years ago

The Insurance Institute reports that the mean amount of life insurance per household in the US is $110,000. This follows a norma

nata0808 [166]

Answer:

a) $\sigma_{\bar X} = \frac{\sigma}{\sqrt{n}}= \frac{40000}{\sqrt{50}}= 5656.85$

b) Since the distribution for X is normal then we know that the distribution for the sample mean $\bar X$ is given by:

$\bar X \sim N(\mu, \frac{\sigma}{\sqrt{n}})$

c) $P( \bar X >112000) = P(Z>\frac{112000-110000}{\frac{40000}{\sqrt{50}}}) = P(Z>0.354)$

And we can use the complement rule and we got:

$P(Z>0.354) = 1-P(Z$

d) $P( \bar X >100000) = P(Z>\frac{100000-110000}{\frac{40000}{\sqrt{50}}}) = P(Z>-1.768)$

And we can use the complement rule and we got:

$P(Z>-1.768) = 1-P(Z$

e) $P(100000< \bar X$

And we can use the complement rule and we got:

$P(-1.768$

Step-by-step explanation:

a. If we select a random sample of 50 households, what is the standard error of the mean?

Previous concepts

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 Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".

Let X the random variable that represent the amount of life insurance of a population, and for this case we know the distribution for X is given by:

$X \sim N(110000,40000)$

Where $\mu=110000$ and $\sigma=40000$

If we select a sample size of n =35 the standard error is given by:

$\sigma_{\bar X} = \frac{\sigma}{\sqrt{n}}= \frac{40000}{\sqrt{50}}= 5656.85$

b. What is the expected shape of the distribution of the sample mean?

Since the distribution for X is normal then we know that the distribution for the sample mean $\bar X$ is given by:

$\bar X \sim N(\mu, \frac{\sigma}{\sqrt{n}})$

c. What is the likelihood of selecting a sample with a mean of at least $112,000?

For this case we want this probability:

$P(X > 112000)$

And we can use the z score given by:

$z= \frac{\bar X -\mu}{\frac{\sigma}{\sqrt{n}}}$

And replacing we got:

$P( \bar X >112000) = P(Z>\frac{112000-110000}{\frac{40000}{\sqrt{50}}}) = P(Z>0.354)$

And we can use the complement rule and we got:

$P(Z>0.354) = 1-P(Z$

d. What is the likelihood of selecting a sample with a mean of more than $100,000?

For this case we want this probability:

$P(X > 100000)$

And we can use the z score given by:

$z= \frac{\bar X -\mu}{\frac{\sigma}{\sqrt{n}}}$

And replacing we got:

$P( \bar X >100000) = P(Z>\frac{100000-110000}{\frac{40000}{\sqrt{50}}}) = P(Z>-1.768)$

And we can use the complement rule and we got:

$P(Z>-1.768) = 1-P(Z$

e. Find the likelihood of selecting a sample with a mean of more than $100,000 but less than $112,000

For this case we want this probability:

$P(100000$

And we can use the z score given by:

$z= \frac{\bar X -\mu}{\frac{\sigma}{\sqrt{n}}}$

And replacing we got:

$P(100000< \bar X$

And we can use the complement rule and we got:

$P(-1.768$

8 0

3 years ago

It takes 10 hours to type 4 reports how many hours does it take to type 15 reports

yaroslaw [1]

Answer:37.5 hrs

Step-by-step explanation:

15/4 = 3.75

3.75*10=37.5

6 0

1 year ago

Read 2 more answers

6A.) Write an equation for:64 equals 33 more than a number y

mixas84 [53]

Answer:

a) 64 = y + 33

b) y = 31

Step-by-step explanation:

follow the word problem and solve when needed

5 0

3 years ago

Solve the following equation -2x + 4 = 2 (4x - 3) -3 (-8 + 4x) a.7 b.2 c.-7 d.3