Assume that when adults with smartphones are randomly​ selected, ​57% use them in meetings or classes. If 8 adult smartphone users are randomly​ selected, find the probability that exactly 4 of them use their smartphones in meetings or classes. The probability is

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Answer:

[tex]\huge\boxed{\frac{12}{20}}[/tex]

To find the numerator and denominator, we can set up a proportion where:

x = denominator

x -8 = numerator

[tex]\frac{3}{5} = \frac{x-8}{x}[/tex]

Cross multiply:

[tex]3(x) = 5(x - 8)[/tex]

[tex]3x = 5x - 40[/tex]

Simplify:

[tex]3x - 5x = -40\\\\-2x = -40\\\\x = 20[/tex]

Substitute in this value of x to find the numerator and denominator:

[tex]\frac{(20) - 8}{(20)} = \frac{12}{20}[/tex]

Hope this helped you! :)

[tex] \LARGE{ \boxed{ \rm{ \orange{ Solution:}}}}[/tex]

Let the numerator be x

It is given that,

Then,

⇛ Denominator- 8 = x

⇛ Denominator = x + 8

According to condition -2)

⇛ Fraction = 3/5

⇛ x/x + 8 = 3/5

Cross multiplying,

⇛ 3(x + 8) = 5x

⇛ 3x + 24 = 5x

⇛ 24 = 5x - 3x

⇛ 24 = 24

Flipping it out,

⇛ 2x = 24

⇛ x = 24/2 = 12

Then,

⇛ x + 8 = 12 + 8 = 20

[tex] \large{ \therefore{ \boxed{ \rm{ \pink{Then, \: the \: fraction = \dfrac{12}{20} }}}}}[/tex]

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Answer:

x=0 or x=2 or x=−4 or x= (7)(2)

Step-by-step explanation:

Answer:

5 lawns

Step-by-step explanation:

Firstly, the equation is 25x + 10 = 135

Ezri makes $25 for every lawn she mows (25x) and has an automatic $10 per day (10). In order to make $135 we take what she makes each day and set it equal to 135.

To solve, we subtract 10 from both sides to create 25x = 125. We then divide 25 from both sides to get x=5. This means that Ezri needs to mow 5 lawns in order to make $135.

I hope this is helpful to you!

**To anyone out there seeing this - let me know if you think I made a mistake and I will fix it.**

Answer:

there are many types of polyhedron.

Basically about which one you want to know?

Step-by-step explanation:

Pentahydron. A polyhedron with 5 faces.

Hexahyderon. A polyhedron with 6 faces.

HeptahyderonA polyhedron with 7 faces.

Octahyderon. A polyhedron with 8 faces.

Similarly there are three more...

Please tell me if it was helpful to you.

If not, then ask me again..

Answer:

-19

Step-by-step explanation:

By looking at the 2 numbers provided, -10 and -4, you can work out that there is a gap of 6 numbers as(-4) - (-10) = 6

There are 2 intervals between -10 and -4, so each interval is

6/2 = 3

a gap of 3

This means the number to the left of -4 is -7, then -10 which works.

From there, you count how many intervals there is between -10 and the ?

There are 3 intervals, so you have to decrease -10 by -3x3 or -9

Therefore the ? is -19

Another way is to just count it directly

The number directly left of -10 is going to be -13, then -16 and finally -19

Answer:

4

Step-by-step explanation:

There are 4 reflectional symmetry

Answer:

1,2,5

A,B,E

Intelligence

Study habits

Work schedule

ED2021

Intelligence and study habits could be mitigated by random assignments.

Options A and B are the correct answer.

Random assignment refers to the process of randomly assigning participants to either the treatment or control group in an experiment.

We have,

Random assignment is done to minimize the effect of extraneous variables, such as intelligence and study habits, that could potentially affect the results of the experiment.

By randomly assigning participants to either the treatment or control group, the differences between the two groups are assumed to be due to chance alone.

Variables such as the professor, course textbook, and work schedule are not affected by random assignments.

These variables are considered to be controlled variables that are held constant across both the treatment and control groups.

Thus,

Intelligence and study habits could be mitigated by random assignments.

Learn more about random assignments here:

https://brainly.com/question/26377187

#SPJ3

To convert [tex]24.123[/tex] in base 8, also notated with [tex]24.123_8[/tex] into base 10 simply multiply each digit with 8 to the power of its position relative to the decimal point.

So,

[tex]24.123_8=2\cdot8^1+4\cdot8^0+1\cdot8^{-1}+2\cdot8^{-2}+3\cdot8^{-3}=20.162109375_{10}[/tex]

Hope this helps :)

Answer:

There are six terms in the series

Step-by-step explanation:

We can see that n starts from 0, and ends at 5. There are therefore 6 terms in this series - as 0 is included. Therefore there will be 6 terms in this series, not 5.

There are six terms in the given series.

Answer:

solution (-2, 5/3  ).

Step-by-step explanation:

Given : y =  + 3  and x = –2.

To find : What is the solution to the system of equations.

Solution : We have given that y = + 3 ------equation (1)

and                                            x = –2.   ------equation (2)

On plugging the x = -2 in equation (1)

y =  + 3

y =  + 3 .

On simplification we get ,

y = .

Therefore, solution (-2, 5/3 ).

Answer: 25 cm

Step-by-step explanation: 6 meters = 600 cm

600 / 24 = 25

Answer:

132 kilo meters

Step-by-step explanation:

Pro por tions:

9 lite rs ⇒ 99 km

12 lite rs  ⇒  P km

P = 99*12/9

P = 132 km

Answer:

132

Step-by-step explanation:

give person above brainliest :))

Answer:

Each item could be included in a set or not included. That gives 2^5 = 32 ways to choose sets, including 1 set with no items, 5 sets of 1 item, 10 sets of 2 items, 10 sets of 3 items, 5 sets of 4 items, and 1 set of 5 items.

9514 1404 393

Answer:

  x > -1 and x ≠ 3

Step-by-step explanation:

The function value will be positive when there are an even number of negative factors. The factors change sign at x = -1, are zero at x = 3. The expression is positive for ...

  x > -1 and x ≠ 3

Answer:

d. 27 cubic feet

Step-by-step explanation:

volume of cube = s^3 = B * s

volume of pyramid = (1/3) * B * h

The volume of a pyramid is 1/3 of the area of the base multiplied by the height. The volume of a cube is the area of the base multiplied by the height. Since the volume of a pyramid has the fraction 1/3 and the volume of the cube does not, then the volume of a cube is 3 times greater than the volume of a pyramid that fits inside and has the same base area.

volume of pyramid = 9 cu ft

volume of cube = 3 * 9 cu ft = 27 cu ft

Answer: d. 27 cubic feet

Answer:

27 ft^3 (Answer d)

Step-by-step explanation:

Here the volume of the pyramid is (1/3) the volume of the cube:

Letting s represent the length of one side of the base,

(1/3)(s)^2(s) = 9 ft^3, equivalent to  s^3 = 27.

Solving for s, we get s = 3 ft.

Thus, the volume of the cube is V = s^3 = (3 ft)^3 = 27 ft^3 (Answer d)

Answer:

4

Step-by-step explanation:

if x+2 is a factor of the above expression then,

x=-2

so putting the value of x in above expression we get,

(-2)^3+2×(-2)^2+2×(-2)+k=0

or,-8+8-4+k=0

k=4

Answer:

Step-by-step explanation:

If (x + 2) is a factor of a polynomial then ( - 2 ) is the zero of that polynomial ⇒ ( - 2 )³ + 2( - 2 )² + 2( - 2 ) + k = 0 ⇒ k = - 4

Answer:

The 90 % confidence limits are (-2.09, 8.09).

Since the calculated values do not lie in the critical region we accept our null hypothesis.

Step-by-step explanation:

The null and alternative hypothesis are given by

H0: σ₁²= σ₂² against Ha: σ₁² ≠ σ₂²

Confidence interval for the population mean difference is given by

(x`1- x`2) ± t √S²(1/n1 + 1/n2)

Where S ²= (n1-1)S₁² + S²₂(n2-1)/n1+n2-2

Critical value of t with n1+n2-2= 50+ 35-2= 83 will be -1.633

Now calculating

S ²=34* (12.8)²+ (14.6)²*49/83= 192.96

Now putting the values in the t- test

(75.1 -72.1) ± 1.633 √ 192.96(1/35 +1/50)

=3 ±  5.09

=-2.09, 8.09  is the 90 % confidence interval for the difference

The 90 % confidence limits are (-2.09, 8.09).

Since the calculated values do not lie in the critical region we accept our null hypothesis.

Answer:

squaring a number is multiplying it by itself twice and cubing a number is multiplying the number three times itself

Step-by-step explanation:

for example 2²=2×2

=4

and 2³=2×2×2

=8

Answer:

Step-by-step explanation:

Given  1 caplet = 325 mg of medication, to calculate the number of caplet 975mg of medication will contain, we will follow the steps below;

Let  1 caplet = 325 mg of medication

x caplet = 975 mg of medication

Cross multiply

325 * x = 1 * 975

325x = 975

Divide both sides by 325

325x/325 = 975/325

x = 3

Hence 3 caplets contains 975 mg of medication.

Answer:

Section I test scores are more dispersed that that of section II.

Step-by-step explanation:

Consider the data collected from the arithmetic test given to two sections of a school.

Section I: Mean = 45, Standard  Deviation = 6.5

Section II: Mean = 45,  Standard deviation = 3.1

The mean of both the sections are same, i.e. 45.

So there is no comparison that can be made from the center of the distribution.

The standard  deviation for section I is 6.5 and the standard  deviation for section II is 3.1.

The standard deviation is a measure of dispersion, i.e. it tells us how dispersed the data is from the mean or how much variability is present in the data.

The standard  deviation for section I is higher than that of section II.

So, this implies that section I test scores are more dispersed that that of section II.

Answer:

mass = 9a^5

center of mass = [tex]\frac{7a}{12}, \frac{7a}{12}, \frac{7a}{12}[/tex]

Step-by-step explanation:

Finding the mass of the solid E

given density function : p ( x,y,z ) = [tex]9x^2 + 9y^2 + 9z^2[/tex]

Mass =   [tex]\int\limits^a_0 \int\limits^a_0 \int\limits^a_0 {9(x^2+y^2+z^2)} \, dx dydz[/tex]   [tex]= \int\limits^a_0 \int\limits^a_0 {9(\frac{a^3}{3}+ay^2+az^2 )} \, dydz[/tex]

         [tex]= \int\limits^a_0 {9(\frac{a^4}{3}+\frac{a^4}{3} +a^2z^2 )} \, dz[/tex]  [tex]= \int\limits^a_0 {9(\frac{2a^4}{3}+a^2z^2 )} \, dz[/tex]  [tex]= 9 ( \frac{2a^5}{3} + \frac{a^5}{3} )[/tex]  

( taking limits as a and 0 )

hence Mass = 9 [tex](a^5)[/tex]

finding the center of mass

attached below is solution

If y = y(x), then the derivative with respect to x is dy/dx. Differentiating both sides of the given equation gives

d/dx [4x ² + y ²] = d/dx [36]

8x + 2y dy/dx = 0

2y dy/dx = -8x

dy/dx = -4x/y

The turning points of the curve, taken as a function of x, are those points where the derivative vanishes.

-4x/y = 0   ===>   x = 0

This value of x corresponds to two points on the curve,

4×0² + y ² = 36   ===>   y ² = 36   ===>   y = ±6

So there are two turning points, (0, -6) and (0, 6).

Answer:

Coefficient of Correlation

Step-by-step explanation:

Coefficient of Correlation is a value that ranges between -1 to 1, which is used to denote the closeness or linear relationship between two variables.

The closer the value of the coefficient is to -1 or 1, the stringer the relationship that exists between two variables.

A negative value suggests a negative relationship. Which means, as one variable decreases, the other variable increases.

A positive coefficient of correlation shows a positive relationship between two variables. Which means, as one variable increases, the other also increases.

If the Correlation coefficient is 0, it means there's no relationship between the variables.

Answer:

  -3 (removable), +5

Step-by-step explanation:

Maybe you have ...

  [tex]f(x)=\dfrac{x+3}{x^2-2x-15}=\dfrac{x+3}{(x+3)(x-5)}=\dfrac{1}{x-5}\quad x\ne-3[/tex]

This will have discontinuities (points where the function is undefined) at ...

The discontinuity as x = -3 is removable by defining f(-3) = -1/8.

Answer:

I've attached a graph with this, that's your answer

Answer:

6:10 pm

Step-by-step explanation:

she skate for 2 h and 14 min so,

8:24- 2:14

=6:10 pm

Answer:

Simplify:

[tex]-4^2-5(1^3)[/tex]

So you get:

[tex]-21\\[/tex]

Answer:

[tex]\huge\boxed{-21}[/tex]

Step-by-step explanation:

-x²-5y³

Given that x = 4, y = 1

[tex]-(4)^2-5(1)^3[/tex]

[tex]-16-5(1)\\-16-5\\-21[/tex]