Can someone help me please

Answer:

A) 99.74%

B) 633.6 hours and 986.4 hours

Step-by-step explanation:

Solution :

Given that ,

mean =  u =810

standard deviation = sigma  = 90    

P(540< x <1080 ) = P[(540-810) /90 < (x - u   ) /  sigma < (1080-810) /90 )]

= P( -3< Z < 3)

= P(Z <3 ) - P(Z < -3)

Using z table    

=0.9987-0.0013

= 0.9974

answer=99.74%

(B)

middle 95% of score is

P(-z < Z < z) = 0.95

P(Z < z) - P(Z < -z) = 0.95

2 P(Z < z) - 1 = 0.95

2 P(Z < z) = 1 + 0. 95= 1.95

P(Z < z) = 1.95/ 2 = 0.975

P(Z <1.96 ) = 0.975

z  ±1.96    

Using z-score formula  

x= z * sigma  +  u

x= -1.96* 90+810

x= 633.6

Using z-score formula  

x= z * sigma  +  u

x=1.96* 90+810

x= 986.4

633.6 hours and 986.4 hours

Answer:

2/5 :)

Step-by-step explanation:

58+2=60+25=85-25=60 60 = 2/5

The solution is 5/17

The probability that the next customer will pay with a debit card is given by the equation A = 5/17

What is Probability?

The probability that an event will occur is measured by the ratio of favorable examples to the total number of situations possible

The value of probability lies between 0 and 1

Given data ,

Let the probability that the next customer will pay with a debit card be A

Now , the equation will be

The number of customers who paid cash last week = 58 customers

The number of customers who used debit card last week = 25 customers

The number of customers who used credit card last week = 2 customer

So ,

The total number of customers = 58 + 25 + 2

The total number of customers = 85 customers

Now , the probability that the next customer will pay with a debit card A = number of customers who used debit card last week / total number of customers

Substituting the values in the equation , we get

Probability that the next customer will pay with a debit card A = 25 / 85

On simplifying the equation , we get

Probability that the next customer will pay with a debit card A = 5 / 17

Therefore , the value of A is 5/17

Hence , the probability is 5/17

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Answer:

Step-by-step explanation:

Area of the circle = 1400π

ie. πr^2 = 1400π . ie r^2 =1400. So r=10√14

Area A = πr^2.Differentiate w.r.t.t

dA/dt = 2πr. dr/dt

900 = 2×π×10√14 .dr/dt

So. dr/dt = 900/2×π×10√14 = 45/π√14 m/sec.

Hope this answer helps you :)

Have a great day

Mark brainliest

Answer:

x = 49

Step-by-step explanation:

x/7 = 7

Multiply each side by 7

7* x/7 =7* 7

x = 49

Step-by-step explanation:

Given that,

A box is created from a sheet of cardboard 40in. on a side by cutting a square from each corner and folding up the sides.

Let x represent the length of the sides of squares removed from each corner.

(a) The volume of a cuboid is given by :

V = lbh

Put values,

V = x(40-2x)(40-2x)

(b) (40-2x) = -2(x-20)

So,

V = x(40-2x)(40-2x)

= [tex]4x\left(x-20\right)^2[/tex]

(c) [tex]4x\left(x-20\right)^2=4x^3-160x^2+1600x[/tex]

It is a cubic polynomial. Its degree is 3.

4/9 of the students are boys thus 5/9 students are girls.

Let " x " be the number of all students.

So we have :

5/9 × x = 90

Multiply both sides by 9/5

5/9 × 9/5 × x = 90 × 9/5

1 × x = 9 × 9 × 10 × 1/5

x = 81 × 2

x = 162

_______________________________

number of boys = 4/9 × x

n o boys = 4/9 × 162

n o boys = 162/9 × 4

n o boys = 18 × 4

n o boys = 72

Answer:

the are would be 18

Step-by-step explanation:

bc 2x3=6 and then 4x3=12 so 12+6=18

Answer:

1/2  1/100

Step-by-step explanation:

One half of one tenth is  [tex]\frac{1}{20}[/tex] fraction.

A number that expresses parts of a whole object or a set of objects is known as a fraction.

Given

One half of one tenth

Rewriting in mathematical form

= [tex]\frac{1}{2} (\frac{1}{10} )[/tex]

= [tex]\frac{1}{20}[/tex]

Hence, One half of one tenth is  [tex]\frac{1}{20}[/tex] fraction.

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Answer:

length : 37 m

width : 8 m

Step-by-step explanation:

perimeter = 2×l(ength) + 2×w(idth) = 90

l = 5w - 3

=> 2×(5w-3) + 2w = 90

10w - 6 + 2w = 90

12w = 96

w = 8

=> l = 5w - 3 = 5×8 -3 = 40-3 = 37

Answer:

$15 per hour

Step-by-step explanation:

30 hours per week x 52 weeks in a year = 1560 hours per year

23,400 / 1560 = $15 per hour

volume = length x width x height

volume = 5m x 6m x 3m = 90 m³

Answer:

Step-by-step explanation:

first no answer=1/4*8/-7 =8/-28

second no answer=6/-5*7/2 =42/-10

9514 1404 393

Answer:

  x = 12

Step-by-step explanation:

The rule here is that the product of the lengths from the external point of intersection (angle vertex) to the intersections with the circle is the same for both secants. The tangent counts as intersecting the circle twice. So, we have ...

  (6)(6) = (3)(x)

  x = 36/3 = 12 . . . . . divide by the coefficient of x

Answer:

Replace the variable x with −1

in the expression.

f(−1)=−(−1)²−1

Simplify −(−1)²−1.

Remove parentheses.

−(−1)²−1

Multiply −1 by (−1)²

by adding the exponents.

(−1)³−1

Raise −1 to the power of 3.

−1−1

Subtract 1 from −1.

−2

Step-by-step explanation:

Hope it's right

Answer:

Answer. = 176 m sq.

Step-by-step explanation:

Hope it helps you

Have a nice day

Answer:

150 square feet

Step-by-step explanation:

12 1/2 * 12 = 150

Answer:

Step-by-step explanation:

a.12÷36/7=7/3

12*7/36

84/36

7/3

b.let the number be x

x*1/2=x/2

x*1/2

x/2

A- True

12÷36/7 = 2.333...

7/3 = 2.333....

Hence it's true

B- True

Consider Any random number eg 10

multiplying it by 1/2 gives 5

and dividing by 2 also gives 5

hence it's true.

C- False

3/2 = 1.5

multiplying it to any number will produce half of the number more.

Answer:

About 44.64.

Step-by-step explanation:

Variance and standard deviation:

The standard deviation is the square root of the variance.

In this question:

Variance of 1992.8. So

[tex]s = \sqrt{1992.8} = 44.64[/tex]

So about 44.64.

Answer:

Red and blue is the correct answer

Step-by-step explanation:

Answer:

800 Books were signed out

Step-by-step explanation:

20% of 4000 is 800

Hi there!  

»»————-　★　————-««

I believe your answer is:

800 books.

»»————-　★　————-««  

Here’s why:  

⸻⸻⸻⸻

[tex]\boxed{\text{20 Percent of 4,000:}}\\\\\rightarrow 4,000* (20/100)\\\\\rightarrow \boxed{800}[/tex]

⸻⸻⸻⸻

There should be 800 books that were teen romance.

»»————-　★　————-««  

Hope this helps you. I apologize if it’s incorrect.  

Answer:

The right answer is "[tex]0.2<\mu d<7.2[/tex]".

Step-by-step explanation:

The given values are:

[tex]\bar{x_0} = 3.7[/tex]

[tex]s_o=4.95[/tex]

[tex]t_{\frac{0.05}{2} }=2.2621[/tex]

As we know,

95% confidence for [tex]\mu_0[/tex] will be:

= [tex]\bar{x_0} \pm t_{\frac{0.05}{2} },n-1\times \frac{s_o}{\sqrt{n} }[/tex]

The lower bound will be:

= [tex]3.7-2.2621\times \frac{4.95}{\sqrt{10} }[/tex]

= [tex]0.16\simeq 0.2[/tex]

The upper bound will be:

= [tex]3.7+2.2621\times \frac{4.95}{\sqrt{10} }[/tex]

= [tex]7.23\simeq7.2[/tex]

Thus the right answer is "[tex]0.2<\mu d<7.2[/tex]"

Answer:

Option D.

Step-by-step explanation:

Domain and range of inverse function:

The domain of the inverse function(x values) is the range(y values) of the original function.

The range of the interse function(y values) is the domain of the original function(x values).

Original function:

Domain: [tex]x \geq 0[/tex]

Range: [tex]y \leq -1[/tex]

Inverse function:

x values in the domain of the inverse function are the y values in the range of the original function. So

Domain: [tex]x \leq 1[/tex]

Same for range(exchange of y and x).

Range: [tex]y \geq 0[/tex]

The answer is given by option D.

Answer: A three-dimensional figure has a length, a width, and a height. A net is a two-dimensional pattern of a three-dimensional figure, that can be folded to form the figure. Identify the net that we could fold in order to create this 3D figure. Match the 3D figure to the right with its appropriate net, below.

Answer:

Step-by-step explanation:

Height= 1 foot

Radius= 1 foot

Density= 60 pounds per cubic foot

Density = mass/ volume

Vol of cone= 1/3× 22/7 ×(radius^2)

=1/3×22/7×1×1

=22/21

Mass=volume × density

= 22/21 × 60

=440/7

Energy = mgh

= 440/7 ×10 × 1

= 628.57 foot pounds

Answer:

64

Step-by-step explanation:

[tex] (\frac{m^{2} }{m + 3} )^{3} \\ = \frac{m^{6} }{(m + 3)^{3} } \\ = \frac{6 {}^{6} }{{9 {}^{3} } } [/tex]

46656/729

= 64

Answer:

Average strength of bond = 8.08 (Approx.)

Step-by-step explanation:

Given data;

11.5  12.1  9.9  9.3  7.8  6.2  6.6  7.0  13.4  17.1  9.3  5.6  5.7  5.4  5.2  5.1  4.9  10.7   15.2  8.5  4.2  4.0  3.9  3.8  3.6  3.4  20.6  25.5  13.8  12.6  13.1  8.9  8.2  10.7  14.2  7.6  5.2  5.5  5.1  5.0  5.2  4.8  4.1  3.8  3.7  3.6  3.6  3.6

Find:

Average strength of bond

Computation:

Average mean = Sum of all observation / Number of observation

Average strength of bond = [11.5 + 12.1 + 9.9 + 9.3 + 7.8 + 6.2 + 6.6 + 7.0 + 13.4 + 17.1 + 9.3 + 5.6 + 5.7 + 5.4 + 5.2 + 5.1 + 4.9 + 10.7 +  15.2 + 8.5 + 4.2 + 4.0 + 3.9 + 3.8 + 3.6 + 3.4 + 20.6 + 25.5 + 13.8 + 12.6 + 13.1 + 8.9 + 8.2 + 10.7 + 14.2 + 7.6 + 5.2 + 5.5 + 5.1 + 5.0 + 5.2 + 4.8 + 4.1 + 3.8 + 3.7 + 3.6 + 3.6 + 3.6] / 48

Average strength of bond = [387.8] / 48

Average strength of bond = 8.0791

Average strength of bond = 8.08 (Approx.)