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3 years ago

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Mathematics

2 answers:

nevsk [136]3 years ago

4 0

#Personal computer:-

Total=480

Percent

$\\ \bull\sf\dashrightarrow \dfrac{480}{1500}\times 100$

$\\ \bull\sf\dashrightarrow 32\%$

#Pacemaker:-

$\\ \bull\sf\dashrightarrow 0.26(1500)$

$\\ \bull\sf\dashrightarrow 390$

#Wireless communication:-

$\\ \bull\sf\dashrightarrow 0.18(1500)$

$\\ \bull\sf\dashrightarrow 270$

#Television:-

Percent

$\\ \bull\sf\dashrightarrow \dfrac{150}{1500}\times 100$

$\\ \bull\sf\dashrightarrow 10\%$

#Others

100-(10+18+26+32)=100-86=14%

$\\ \bull\sf\dashrightarrow 0.14(1500)$

$\\ \bull\sf\dashrightarrow 225$

olga2289 [7]3 years ago

3 0

Answer: Check out the filled out diagram below.

===================================================

Explanation:

To get the percentage, we divide the actual number by the total surveyed. This produces the decimal form of the percentage. Don't forget to move the decimal point 2 spots to the right to convert to the percentage.

For the first row, we have 480 people out of 1500 who said the personal computer was the most important invention.

So, 480/1500 = 0.32 = 32% of the people surveyed say the personal computer was the most important invention.

The fourth row will be handled the same way:

150/1500 = 0.10 = 10%

-------------

To go from a percentage to the actual number, we'll multiply the decimal form of the percentage by the number surveyed.

26% chose pacemaker, so 0.26*1500 = 390 people chose this item. Notice that 390/1500 = 0.26 = 26%

For the the third row, we have 0.18*1500 = 270 people who chose wireless communication as the most important.

-------------

To deal with the last row labeled "other", you'll need to keep in mind that percentages always add up to 100% as that's the highest it can go in many practical situations.

The percentages we calculated so far were: 32%, 26%, 18%, 10%

Those percentages add to: 32%+26%+18%+10% = 86%

The missing item must be 14% since 100% - 86% = 14%

Therefore, 14% of the 1500 people surveyed picked "other".

14% of 1500 = 0.14*1500 = 210 will go in the "actual number" column for this bottom row. Notice that 210/1500 = 0.14 = 14%

Also, notice that all the values in the "actual number" column add up to 1500

480+390+270+150+210 = 1500

This helps confirm our answers.

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15 is 30% of what number?

dangina [55]

#1---> let the number you are trying to find be x for the following questions

30%*x=15
x=15/30%
x=50

#2
10%*x=14
x=14/10%
x=140

#3
(4/32)*100
is the same as (1/8)*100= 12.5%

#4
1%* x=11
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by the way * means multiply

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3 years ago

Find a recursive formula for the sequence:<br><br> 1, -1, -7, -25

Mumz [18]

<h3>Answer:</h3>

$a_n=3a_{n-1}-4$

<h3>Step-by-step explanation:</h3>

<em>Try the answers</em>

You can try the answers to see what works. You can expect all of the choices to match the first two terms, so try some farther down. Let's see if we can get -25 from -7.

a) 3*(-7) -4 = -21 -4 = -25 . . . . this one works

b) -7 -2 = -9 . . . . ≠ -25

c) -3(-7) +2 = 21 +2 = 23 . . . . ≠ -25

d) -2(-7) +1 = 14 +1 = 15 . . . . ≠ -25

The formula that works is the first one.

_____

<em>Derive it</em>

All these formulas depend on the previous term only, so we can write equations that show the required relationships. Let the unknown coefficients in our recursion formula be p and q, as in ...

$a_n=p\cdot a_{n-1}+q$

Then, to get the second term from the first, we have

... 1·p +q = -1

And to get the third term from the second, we have

... -1·p +q = -7

Subtracting the second equation from the first gives ...

... 2p = 6

... p = 3 . . . . . . . this is sufficient to identify the first answer as correct

We can find q from the first equation.

... q = -1 -p = -1 -3 = -4

So, our recursion relation is ...

$a_n=3a_{n-1}-4$

6 0

3 years ago

What percent is equivalent to 9/4 ?<br> A) .225%<br> B) 22.2%<br> C) 44.4%<br> D) 225%

ki77a [65]

Your answer would be D. 225%. 9/4 equals to 2.25 which multiplied but a 100 to make the percentage equals 225%.

8 0

3 years ago

A local eat-in pizza restaurant wants to investigate the possibility of starting to deliver pizzas. The owner of the store has d

Alinara [238K]

Answer:

Read step by step explanation

Step-by-step explanation:

The owner already knows that the limit for the average time delivered pizzas is 38 minutes. So we conclude

1.-The resulting mean from sample data ( x ) ( 27 customers) need to be smaller than 38 minutes, any value of sample above 38 minutes means more time for the delivery action and will indicate a failure for the future project

2.-As sample size is smaller than 30 the test has to be t-student one tail test to the left

Test hypothesis

Null hypothesis H₀ x = 38

Alternative hypothesis Hₐ x < 38

We should test at a significance level α = 0,05 (α = 5%)

If the result of the test is to accept H₀ delivery project won´t be implemented, if on the other hand, H₀ is rejected then in the condition of the alternative hypothesis we accept Hₐ the sample indicates that we have a smaller average time than 38 minutes.

4 0

3 years ago

Suppose some country had an adult population of about 46 million, a labor-force participation rate of 75 percent, and an unemplo

Rus_ich [418]

Answer:

31.74 million people were employed.

Step-by-step explanation:

The unemployment rate is the number of unemployed people divided by the size of the labor force.

So the first step to solve this problem is finding the size of the country's labor force.

Suppose some country had an adult population of about 46 million, a labor-force participation rate of 75 percent.

So the size of the country labor force is:

0.75 * 46 million = 34.5 million people.

Unemployment rate of 8 percent. How many people were employed?

This means that 100 - 8 = 92 percent of people were employed. Remembering, this considers only the labor force, of 34.5 million people. So

0.92 * 34.5 million = 31.74 million

31.74 million people were employed.

5 0

3 years ago