A certain brand of flood lamps has a lifetime that is normally distributed with a mean
of 3,750 hours and a standard deviation of 300 hours.

(a) What proportion of these lamps will last for at least 4,000 hours?

(b) What proportion of these lamps will last between 3,600 and 4,000 hours?

(c) What proportion of these lamps will last less than 3,800?

Answers

Answer 1

Answer:

0.83

Step-by-step explanation:

(a) z = (x - mean) / sd = (4000 - 3750) / 300 = 0.83

This corresponds to 0.7967 from the z-table, which represents how many last less than 4000 hours, so the answer is 1 - 0.7967 = 0.2033

(b) It will be P(x<4000) - P(x>3600) = 0.7967 - whatever the corresponding value is.

(c) same procedure as (b).

(d) 2% above corresponds to 0.02 which is a z-score of -2.05

-2.05 = (x - 3750) / 300

x = 3135


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I need help with Algebra 2. Thank you! :)

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Answer:

B: 6.0

Step-by-step explanation:

-3t^2+9t+54 = 0

This is the equation that needs to be solved

Divide both sides by -3

t^2 - 3t - 18 = 0

The factors of 18 are: (1 18) (2 9) (3 6)

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So: (t + 3) (t - 6) = 0

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simplify [tex]\sqrt{p^4q^6r^5. answer is D just took the test

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The answer is A according to the answer and the sheet

The perimeter of the shape below is 44 feet. What is the area in square feet?

Answers

Answer:

2(4x+2+6x)=44

10x+2=22

10x=20

x=2

area= 10*12=120sq feet

Step-by-step explanation:

Find the volume of the cylinder.
Either enter an exact answer in terms of or use 3.14 for pi

Answers

Answer:

Answer in explanation

Step-by-step explanation:

Volume of cylinder =

[tex]\pi {r}^{2} h \\ = (3.14)(4) {}^{2}(8) \\ = 401.92units {}^{3} \: or \: 128\pi \: units^{3} [/tex]

Answer:

Step-by-step explanation:

Radius r = 4

Height h = 8

Volume = πr²h = 128π units³

Hellllp!


Ahmed needs to cover a box that is 6 cm long, 4 cm high and 4 cm wide with

material on all sides. How much material does he need?



Will mark as brainlist
Thaaaaaanks

Answers

Answer:

he needs 128cm² materials

Step-by-step explanation:

surface area of cuboid =2(lb+bh+lh)

=2(6×4+4×4+6×4)=128cm²

Help me out please!!!!!!!!

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Answer:

its d

Step-by-step explanation:

it so easy it say it on the chart

20 baseballs pitched he hit 17. What %did TJ hit

Answers

Percent part
100 Whole

x 17
100 20

(100*17)/20
1700/20
=85 percent

I NEED HELP QUICK!!!

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Answer: 12cm

Step-by-step explanation:

top earning app/game of usa​

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Answer:

Pokemon Go

Step-by-step explanation:

¿? :v :v :v

¿? :v :v :v

PLEASE LOOK AT THE IMAGE BELOW! (I MARK BRAINLIEST!)

Answers

Answer:

- 7 < - 5

Step-by-step explanation:

Because negative 7 is technically lower than negative 5. Due to them being negative the more closer you are to -1 the more higher of a number it is. I don't know how to explain it but I hope that it makes sense!

Have a wonderful day! <33

The following is the estimation results for a multiple linear regression model:
Y = B. + ,X,+B,X, +E
SUMMARY OUTPUT
Regression Statistics
R-Square 0.558
Regression Standard Error (S) 863.100
Observations 35
Coeff StdError t-stat
Intercept 1283.000 352.000 3.65
X1 25.228 8.631
X2 0.861 0.372
Questions:
1. Write the fitted regression equation (30 points).
2. Write the estimated intercepts and slopes, associated with their corresponding standard errors (30 points).
3. Interpret each coefficient (40 points).

Answers

Answer:

Kindly check explanation

Step-by-step explanation:

Given the summary output :

_______ Coeff___ StdError__ t-stat

Intercept 1283.000_ 352.000 _ 3.65

X1 _____ 25.228 ____8.631

X2 _____0.861 _____0.372

General form of a multiple regression model:

Y = B1X1+B2X2 +E

The fitted regression equation is :

y = 25.228X1 + 0.861X2 + 1283

Intercept and slope corresponding to the standard error :

Intercept = 352

Slope 1 = 8.61 ; slope 2 = 0.372

'B' coefficient represents the change in the mean response, Y, per unit increase in a version predictor variable when all the other predictors are held constant.

B1 represents the change in the mean response, U, per unit increase in x1 when x2, x3, ..., xk are held constant

B2 represents the change in the mean response, U, per unit increase in x2 when x1, x3, ..., xk are held constant

help please i will award brainliest

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Answer:

D 826.80

Step-by-step explanation:

Answer:

$780.00

Step-by-step explanation:

just add 420+360= $780.00

Brenda and her three friends ate dinner at Applebee’s. Their total bill was $24.36 which they spent equally. How much does each person pay?
plz explain how you got your answer

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Answer:

8.12

Step-by-step explanation:

determine whether the equation is exponential growth or exponential decay

1a. y = 2(11/5)^-x

2b. y= e^-2x

3c. y= 1/4e^x​

Answers

9514 1404 393

Answer:

decaydecaygrowth

Step-by-step explanation:

If the base of a positive exponential is greater than 1, the function is a growth function. If it is less than 1, the function decays.

Remember that a^-1 = 1/a, so a negative exponential can be transformed to a positive one.

__

1. y = 2(11/5)^-x = 2(5/11)^x . . . . 5/11 < 1, so decay

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_____

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Lisa is saving money to buy a game. The game costs $36, and so far she has saved three-fourths of this cost. How much money has Lisa saved?

Answers

36 multiplied by (3/4) is 27 dollars
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Can I get brainliest

PLEASE SAY A,B,C OR D OF THE RIGHT ANSWER ONLY PLEASE! no links or flies, x .

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A. 7/12 + 4/12 = 11/12

B. 7/12 – 4/12 = 3/0

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D. 7/12 – 4/12 = 3/12

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Answer:

it should be C if not I'm so so sry

Where are my smart friends?? I had $370.00. My Mom gave $150.00. My Dad gave $150.00. My Aunt and Uncle gave me $100.00. I had another $30.00. How much did I have? ​

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Answer:

im ur smart friend

Step-by-step explanation:

370.00 plus 150.00 equals to 520.00

520.00 plus another 150.00 equals to 670.00

670.00 plus 100.00 equals to 770.00

770.00 plus 30.00 equals to $800.00 total

Answer: $800 total

Answer: it says had so its $400

Step-by-step explanation:

Its 370+30=400

easiest way to make a ratio into percentage

Answers

Answer:

To convert a ratio into the form of a percentage

Answer:

Simply divide m by n and then multiply the result by 100.

Example: 12 : 4 = 300%

can someone help me please

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Answer:

Step-by-step explanation:

Answer:

The correct answer is B. $6.50 per pound.


On a math test, students
earn 4 points for each correct answer and lose 1 point
for each incorrect answer. If there are 50 questions on
the test, a student's score is shown by the expression
4(50 - w) - w, where w is the number of wrong
answers. Chris says that the expression 5(40 - w) could
also be used. Is he correct? Why or why not? Show your work.

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Yes, because they both equal to 200

The price of XYZ stock fluctuates widely. In January it closed at $3.50 but In February it Closed at $2.25. However at the end of March it shot back up to $5.00.

What was the average monthy change in the price of XYZ stock from january through march?

Answers

Answer:

$3.583

Step-by-step explanation:

Given the monthly stock prices :

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February = $2.25

March = $5.00

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What is the height of a rectangle with a perimeter of 152.8 mm and base
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Answers

Answer:
4.2

Step:
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I think it’s angle D because it’s an alternate interior angle with angle B

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A student usually saves $20 a month. He would like to reach a goal of saving $350 in 12 months. The student writes the equation
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• Show your work or explain your answer.
Write your answer as a sentence that describes what the variable x represents.

Answers

Answer:

Step-by-step explanation:

350=12(x+20)

(divide both sides by 12)

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(subtract 20 from both sides)

x=9.16667

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15%= .15

.15*22= 3.3

Answer: 3.30

Hi please help me with this asap.​

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a. 15% of $20000 is 15/100x20000 = $3000. You therefore get $3000 off the $20000 asking price. $17000

b. VAT is 10%. 10/100x17000 = $1700
You therefore add $1700 to the discounted price of $17000. $18700

c. 15% off the discounted price. 15/100 x17000 = $2550. New discounted price is $17000-2550= $14450.

d. 10% VAT of $14450 is 10/100x$14450 = $1445. Total price after all discounts and VAT is now $14450+$1445 = $15895

Use differentials to estimate the amount of material in a closed cylindrical can that is 60 cm high and 24 cm in diameter if the metal in the top and bottom is 0.1 cm thick, and the metal in the sides is 0.05 cm thick. Note, you are approximating the volume of metal which makes up the can (i.e. melt the can into a blob and measure its volume), not the volume it encloses. The differential for the volume is

Answers

Answer:

dV ≈ 927.4 cm³

Step-by-step explanation:

Formula for volume of a cylinder is;

V = πr²h

Using differentials, we have;

dV = (dV/dr)dr + (dV/dh)dh

Now, dV/dr = 2πrh

dV/dh = πr²

Thus, at r = 24/2 = 12 cm

And at h = 60 cm, we have;

dV/dr = 2π(12 × 60)

dV/dr = 4523.89 cm²

Also;

dV/dh = π(12)²

dV/dh = 452.39 cm²

the metal in the top and bottom is 0.1 cm thick. Thus, dr = 2 × 0.1 = 0.2

the metal in the sides is 0.05 cm thick. Thus; dh = 0.05

Thus;

dV = (4523.89 × 0.2) + (452.39 × 0.05)

dV ≈ 927.4 cm³

Right triangle ABC is shown.
Which equation can be used to solve for c?

Answers

Answer:

[tex]\sin(50^\circ)=3/c[/tex]

Step-by-step explanation:

Remember SOH/CAH/TOA. We will use SOH, which means [tex]\sin[/tex] of the angle is equal to the opposite side over the hypotenuse.

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