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3 years ago

Is 21.8 x 10 to the power of 8 a scientific notation

Mathematics

1 answer:

Oksanka [162]3 years ago

8 0

Answer:

$\large\boxed{2.128\times10^9}$

Step-by-step explanation:

The scientific notation:

$a\cdot10^k\\\\1\leq a$

We have:

$21.8\times10^8$

21.8 >10

21.8 = 2.18 × 10

Thereofre:

$21.8\times10^8=2.18\times10\times10^8$

Use

$a^n\cdot a^m=a^{n+m}$

$21.8\times10^8=2.18\times10^1\times10^8=2.18\times10^{1+8}=2.18\times10^9$

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The number of Smart TVs owned by residents in Picayune increased by 25% this year. Assuming that the 824 Smart

masha68 [24]

Answer:

25% of 824

25/100 × 824

206

New prices of the TV is

824+206= 1030

6 0

2 years ago

What is the length from Alaska to Chicago times 5 divided by 3?

Annette [7]

Answer:

14302 miles

Step-by-step explanation:

from alaska to chicago it is 2861 mi.

2861 times 5

that divdied by three is 14302

5 0

3 years ago

Assume that a computer was used to generate the given confidence interval for the population mean. Find the sample mean or margi

stealth61 [152]

Answer:

The sample mean is

b.3.55

The margin of error is

0.32

Step-by-step explanation:

Deep explanation about a confidence interval

We have that to find our $\alpha$ level, that is the subtraction of 1 by the confidence interval divided by 2. So:

$\alpha = \frac{1-0.9}{2} = 0.05$

Now, we have to find z in the Ztable as such z has a pvalue of $1-\alpha$ .

So it is z with a pvalue of $1-0.05 = 0.95$ , so $z = 1.645$

Now, find M as such

$M = z*\frac{\sigma}{\sqrt{n}}$

In which $\sigma$ is the standard deviation of the population and n is the size of the sample.

$M = 1.645*215 = 353.675$

The lower end of the interval is the mean subtracted by M. So it is 6.4 - 0.3944 = 6.01 hours.

The upper end of the interval is the mean added to M. So it is 6.4 + 0.3944 = 6.74 hours.

In this problem:

The deep explanation is not that important.

We just have to recognize that the interval has a lower end and an upper end. The distance from both the upper and the lower end to the mean is M. This means that the sample mean is the halfway point between the lower end and the upper end.

The margin of error is the distance of these two points(lower and upper end) to the mean.

In our interval

Lower end: 3.23

Upper end: 3.87

Sample mean

$M = \frac{3.23 + 3.87}{2} = 3.55$

So the correct answer is:

b.3.55

The margin of error is

3.87 - 3.55 = 3.55 - 3.23 = 0.32

4 0

3 years ago

COMPUTE 3 ( 2 1/2 - 1 ) + 3/10

Juli2301 [7.4K]

Answer:

<h3> $\boxed{ \frac{24}{5} }$ </h3>

Step-by-step explanation:

$\mathsf{3(2 \frac{1}{2} - 1) + \frac{3}{10} }$

Convert mixed number to improper fraction

$\mathrm{3( \frac{5}{2} - 1) + \frac{3}{10} }$

Calculate the difference

⇒ $\mathrm{3( \frac{5 \times 1}{2 \times 1} - \frac{1 \times 2}{1 \times 2} }) + \frac{3}{10}$

⇒ $\mathrm{ 3 \times( \frac{5}{2} - \frac{2}{2}) } + \frac{3}{10}$

⇒ $\mathrm{3 \times ( \frac{5 - 2}{2} ) + \frac{3}{10} }$

⇒ $\mathrm{3 \times \frac{3}{2} + \frac{3}{10} }$

Calculate the product

⇒ $\mathrm{ \frac{3 \times 3}{1 \times 2} + \frac{3}{10} }$

⇒ $\mathrm{ \frac{9}{2} + \frac{3}{10}}$

Add the fractions

⇒ $\mathsf{ \frac{9 \times 5}{2 \times 5} + \frac{3 \times 1}{10 \times 1} }$

⇒ $\mathrm{ \frac{45}{10} + \frac{3}{10} }$

⇒ $\mathrm{ \frac{45 + 3}{10 } }$

⇒ $\mathrm{ \frac{48}{10} }$

Reduce the numerator and denominator by 2

⇒ $\mathrm{ \frac{24}{5} }$

Further more explanation:

Addition and Subtraction of like fractions

While performing the addition and subtraction of like fractions, you just have to add or subtract the numerator respectively in which the denominator is retained same.

For example :

Add : $\mathsf{ \frac{1}{5} + \frac{3}{5} = \frac{1 + 3}{5} } = \frac{4}{5}$

Subtract : $\mathsf{ \frac{5}{7} - \frac{4}{7} = \frac{5 - 4}{7} = \frac{3}{7} }$

So, sum of like fractions : $\mathsf{ = \frac{sum \: of \: their \: number}{common \: denominator} }$

Difference of like fractions : $\mathsf{ \frac{difference \: of \: their \: numerator}{common \: denominator} }$

Addition and subtraction of unlike fractions

While performing the addition and subtraction of unlike fractions, you have to express the given fractions into equivalent fractions of common denominator and add or subtract as we do with like fractions. Thus, obtained fractions should be reduced into lowest terms if there are any common on numerator and denominator.

For example:

$\mathsf{add \: \frac{1}{2} \: and \: \frac{1}{3} }$

L.C.M of 2 and 3 = 6

So, ⇒ $\mathsf{ \frac{1 \times 3}{2 \times 3} + \frac{1 \times 2}{3 \times 2} }$

⇒ $\mathsf{ \frac{3}{6} + \frac{2}{6} }$

⇒ $\frac{5}{6}$

Multiplication of fractions

To multiply one fraction by another, multiply the numerators for the numerator and multiply the denominators for its denominator and reduce the fraction obtained after multiplication into lowest term.

When any number or fraction is divided by a fraction, we multiply the dividend by reciprocal of the divisor. Let's consider a multiplication of a whole number by a fraction:

$\mathsf{4 \times \frac{3}{2} = \frac{4 \times 3}{2} = \frac{12}{2} = 6}$

Multiplication for $\mathsf{ \frac{6}{5} \: and \: \frac{25}{3} }$ is done by the similar process

$\mathsf{ = \frac{6}{5} \times \frac{25}{3} = 2 \times 5 \times 10}$

Hope I helped!

Best regards!

5 0

3 years ago

100 POINTS FOR ANYONE WHO CAN ANSWER THESE! <3

faust18 [17]

Answer:

∠1 = 142°

reason: angles 1 and 2 are supplementary so they equal 180. 180-38 is 142

∠3 = 38°

reason: angles 2 and 3 are adjacent angles because they are diagonal from each other so they will equal the same measure.

∠4 = 142°

reason: since angle 4 is adjacent to angle 1 and is supplementary to angle 3, it has to be 142

∠5 = 38°

reason: since it is a transversal that means both of the intersections are the same measurements. so angle 5 is 38 since it matches up with angle 2

∠6 = 142°

reason: for the same reason as angle 5. angle 6 matches up with angle 1 so it has to equal 142.

∠8 = 142°

reason: since angle 8 is adjacent to angle 6 it has to equal 142. angle 8 is also a transverse angle to angle 4. and since angle 4 also equals 142, 8 has to also

Step-by-step explanation:

hope this helped you :)

8 0

3 years ago