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3 years ago

Find the exact solution of 3x^2+7=28

1 answer:

4 0

$\text{Solve:}\\\\3x^2+7=28\\\\\text{Subtract 7 from both sides}\\\\3x^2=21\\\\\text{Divide both sides by 3}\\\\x^2=7\\\\\text{Square root both sides}\\\\\sqrt{x^2}=\sqrt7\\\\x=\pm\sqrt7\\\\\boxed{x=\sqrt7\,\,or\,\,x=-\sqrt7}$

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A sample of blood pressure measurements is taken for a group of adults, and those values (mm Hg) are listed below. The values

nika2105 [10]

Answer:

For systolic pressure data:

$\bar X =127.2\\\\S=17.91668\\\\CV=\frac{17.91668}{127.2}=0.14085$

For diastolic pressure data:

$\bar X =73.5\\\\S=12.54\\\\CV=\frac{73.5}{12.54}=0.17061$

Systolic pressure is slightly less variable, among individuals in the sample, than diastolic pressure.

Step-by-step explanation:

The coefficient of variation is defined as the percentage relative variation of a set of data with respect to its average. And it is calculated like this:

$CV=\frac{\bar X}{S}$

$S =\sqrt{\frac{1}{n-1} \sum_{i=1}^n (x_i-\bar{x})^2$

$\bar X={\frac{1}{n} \sum_{i=1}^n x_i$

For systolic pressure data:

$\bar X =127.2\\\\S=17.91668\\\\CV=\frac{17.91668}{127.2}=0.14085$

For diastolic pressure data:

$\bar X =73.5\\\\S=12.54\\\\CV=\frac{12.54}{73.5}=0.17061$

It is observed that the systolic pressure shows greater standard deviation but less coefficient of variation. This is due to the greater magnitude of its measurement scale.

Systolic pressure is slightly less variable, among individuals in the sample, than diastolic pressure.

7 0

3 years ago

How much interest is earned for the investment? $20,000 for 2 years at 6% compounded annually

Sunny_sXe [5.5K]

You earn $2,400 in interest over the 2 years

3 0

3 years ago

I need help please!:D

Dafna1 [17]

Answer:

1 & 2

Step-by-step explanation:

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3 years ago

For all values of x, f(x)=2x^2 and g(x)= x+1<br> Solve fg(x) = gf(x)

Andrej [43]

Answer:

-0.25

Step-by-step explanation:

→ Find fg(x)

2 ( x + 1 )² = 2x² + 4x + 2

→ Find gf(x)

2x² + 1

→ Equate them

2x² + 1 = 2x² + 4x+ 2

→ Move everything to the right hand side

0 = 4x + 1

→ Solve

x = -0.25

4 0

2 years ago

Read 2 more answers

The sum of twice a number and 18 is 5 less than three times the number, Write the

topjm [15]

Step-by-step explanation:

Let x represent the number.

We have 2x + 18 = 3x - 5, therefore x = 23.

The number is 23.

8 0

2 years ago