Lightbulbs. A company produces lightbulbs. We know that the lifetimes (in hours) of lightbulbs follow a bell-shaped (symmetric and unimodal) distribution with a mean of 7,161 hours and a standard deviation of 564 hours. Use the Empirical Rule (68-95-99.7 rule) to answer the following question: The shortest lived 2.5% of the lightbulbs burn out before how many hours

Answer:

"D" is the correct answer

Step-by-step explanation:

Answer:

y = 4 x − 4

Step-by-step explanation:

Answer:

80 students

Step-by-step explanation:

Answer:

80

Step-by-step explanation:

60% of 500 = 300

72% of 500 = 360

40% of 500 = 200

28% of 500 = 140

300+360 = 660

660 - 2x = 500

660 - 500 = 2x

160 = 2x

2x = 160

x = 80

Answer:4778.3 cm^3

Step-by-step explanation: The formula for volume of a cone is V=1/3h pi r^2. By plugging in the height and the radius we get our answer.

Answer:

4778.4 :)

Step-by-step explanation:

Answer:

A and b Are in quadrant 2. F and D are in quadrant 1. F is in quadrant 3 and C is in quadrant 4

Step-by-step explanation:

each quadrant is in the boxes and the question is asking what is each  coordinate is in what quadrant

Answer:

This problem has not solution

Step-by-step explanation:

lets the  integers be:

x

x+1

x+2

x+3

so:

x+(x+1)+(x+2)+(x+3)=2021

x+x+x+x+1+2+3=2021

4x+6=2021

4x=2021-6=2015

x=2015/4=503.75

x is not a integer

Hi!

√80 = √(16 • 5) = √(4² • 5) = 4√5

Answer:

[tex]\sqrt{49}[/tex]

Step-by-step explanation:

Define a rational number by a number able to expressed a fraction where the denominator is not 0 or 1.

Non-terminating (never-ending) decimals cannot be expressed as a fraction and therefore are irrational. However, recall that [tex]\sqrt{49}=7[/tex], which can be expressed as a fraction (e.g. [tex]\frac{14}{2}[/tex], etc). Thus, the answer is [tex]\boxed{\sqrt{49}}[/tex].

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

Explanation:

It might help to draw out the picture as shown below. The pool itself (just the water only) is the inner rectangle. The outer rectangle is the pool plus the border of those 1 by 1 tiles.

The pool is a rectangle 90 feet by 80 feet. If we add on the tiles, then we get a larger rectangle that is 90+2 = 92 feet by 80+2 = 82 feet.

We add on 2 since we're adding two copies of "1" on either side of each dimension.

The larger rectangle's area is 92*82 = 7544 square feet

The smaller rectangle's area is 90*80 = 7200 square feet

The difference in areas is 7544-7200 = 344 square feet.

Each 1 by 1 tile is of area 1*1 = 1 sq foot, meaning that 344 tiles will get us the 344 square foot border around the pool.

Answer:

Reduce if needed, asked or necessary

Step-by-step explanation:

1. 4/10

2. 2/6

3. 4/10

4. more likely

Answer:

Since Probability Is Usually Written In Fraction Form OR Ratios

(Although It Really Doesn't Matter):

1.  4/10 (2/5)

2.  2/6  (1/3)

3.  6/10 (3/5)

(All Fraction Form)

Last Question:

I can't really see the bottom but probably its 'More likely' since you can already see a bunch of red marbles.

Step-by-step explanation:

This is the basic fraction form :  ____ / ____

Based on what they ask, like the probability of picking out a black marble, count the number of black marbles in the particular bag and put that number as the numerator. The denominator is the total amount of marbles in that particular bag. Hope this helps!

x+2 in expansion of (x+2) ?

A

Answer:

[tex]x=4[/tex]

Step-by-step explanation:

We have the quadratic function:

[tex]\displaystyle y=0.3(x-4)^2-2.5[/tex]

And we want to determine its axis of symmetry.

Notice that this is in vertex form:

[tex]y=a(x-h)^2+k[/tex]

Where (h, k) is the vertex of the parabola.

From our function, we can see that h = 4 and k = -2.5. Hence, our vertex is the point (4, -2.5).

The axis of symmetry is equivalent to the x-coordinate of the vertex.

The x-coordinate of the vertex is 4.

Therefore, the axis of symmetry is x = 4.

(1) Recall that

sin(x - y) = sin(x) cos(y) - cos(x) sin(y)

sin²(x) + cos²(x) = 1

Given that α lies in the third quadrant, and β lies in the fourth quadrant, we expect to have

• sin(α) < 0 and cos(α) < 0

• sin(β) < 0 and cos(β) > 0

Solve for cos(α) and sin(β) :

cos(α) = -√(1 - sin²(α)) = -3/5

sin(β) = -√(1 - cos²(β)) = -5/13

Then

sin(α - β) = sin(α) cos(β) - cos(α) sin(β) =  (-4/5) (12/13) - (-3/5) (-5/13)

==>   sin(α - β) = -63/65

(2) In the second identity listed above, multiplying through both sides by 1/cos²(x) gives another identity,

sin²(x)/cos²(x) + cos²(x)/cos²(x) = 1/cos²(x)

==>   tan²(x) + 1 = sec²(x)

Rewrite the equation as

3 sec²(x) tan(x) = 4 tan(x)

3 (tan²(x) + 1) tan(x) = 4 tan(x)

3 tan³(x) + 3 tan(x) = 4 tan(x)

3 tan³(x) - tan(x) = 0

tan(x) (3 tan²(x) - 1) = 0

Solve for x :

tan(x) = 0   or   3 tan²(x) - 1 = 0

tan(x) = 0   or   tan²(x) = 1/3

tan(x) = 0   or   tan(x) = ±√(1/3)

x = arctan(0) + nπ   or   x = arctan(1/√3) + nπ   or   x = arctan(-1/√3) + nπ

x = nπ   or   x = π/6 + nπ   or   x = -π/6 + nπ

where n is any integer. In the interval [0, 2π), we get the solutions

x = 0, π/6, 5π/6, π, 7π/6, 11π/6

(3) You only need to rewrite the first term:

[tex]\dfrac{\sin(x)}{1-\cos(x)} \times \dfrac{1+\cos(x)}{1+\cos(x)} = \dfrac{\sin(x)(1+\cos(x))}{1-\cos^2(x)} = \dfrac{\sin(x)(1+\cos(x)}{\sin^2(x)} = \dfrac{1+\cos(x)}{\sin(x)}[/tex]

Then

[tex]\dfrac{\sin(x)}{1-\cos(x)}+\dfrac{1-\cos(x)}{\sin(x)} = \dfrac{1+\cos(x)+1-\cos(x)}{\sin(x)}=\dfrac2{\sin(x)}[/tex]

Answer:

78i+52j

Step-by-step explanation:

8(9i+2j)-6(-i-6j)

72i+16j+6i+36j

=78i+52j

Answer:

Step-by-step explanation:

circumference = πd ≅ 250 ft

d ≅ 250/π ≅80 ft

Answer:

is that the full question?

Answer:

Solution:-

Given,

ab =perpendicular (p)= 6cm

ac =hypotenuse (h)= 12cm

cd =base (b)= ?

using , Pythagoras theorem we have ,

b²=√h²-p²

or,cd²=√ac²-ab²

= √12²-6²

= √144-36

=√108

=√10.8²

=10.8cm

the length of cd is 10.8 cm

hope it is helpful to you

Answer:

3000 is the answer this question.

Answer:

22608 mm³/s

Step-by-step explanation:

Applying chain rule,

dV/dt = (dV/dr)(dr/dt)............... Equation 1

Where dV/dr = rate at which the volume is increasing

But,

V = 4πr³/3

Therefore,

dV/dr = 4πr²............... Equation 2

Substitute equation 2 into equation 1

dV/dt = 4πr²(dr/dt).............. Equation 3

From the question,

Given: dr/dt = 2 mm/s, r = 60/2 = 30 mm

Consatant: π = 3.14

Substitute these values into equation 3

dV/dt = 4×3.14×30²×2

dV/dt = 22608 mm³/s

Answer:

6

Step-by-step explanation:

n(AUB) = n(A) + n(B) - n(AnB)

n(AUB) can have the minimum number of elements if n(AnB) has the maximum number of elements.

n(AnB) maximum = 3

so n(AUB) = 3+6-3 = 6

Answer:

The right answer is "0.3193".

Step-by-step explanation:

According to the question,

Mean,

[tex]\frac{1}{\lambda} = 13[/tex]

[tex]\lambda = \frac{1}{13}[/tex]

As we know,

The cumulative distributive function will be:

⇒ [tex]1-e^{-\lambda x}[/tex]

hence,

In the first 5 years, the probability of failure will be:

⇒ [tex]P(X<5)=1-e^{-\lambda\times 5}[/tex]

                    [tex]=1-e^{-(\frac{1}{13} )\times 5}[/tex]

                    [tex]=1-e^(-\frac{5}{13})[/tex]

                    [tex]=1-0.6807[/tex]

                    [tex]=0.3193[/tex]

Answer:

Step-by-step explanation:

Total sales = x

Correct choice is C

Answer:

C. -4

Step-by-step explanation:

Answer:

(c) - 4

is your right answer

Answer:

[tex]\sqrt[3]{7x}[/tex]

Step-by-step explanation:

Given

[tex]7x[/tex]

Required

The radical statement

Cube root is represented as:

[tex]\sqrt[3]{}[/tex]

Considering [tex]7x[/tex], the expression is:

[tex]\sqrt[3]{7x}[/tex]

Answer:

[tex]\mu = 5.2[/tex]

[tex]\sigma = 2.257[/tex]

Step-by-step explanation:

Given

[tex]n = 260[/tex] -- samples

[tex]p = \frac{1}{50}[/tex] --- one in 50

Solving (a): The mean

This is calculated as:

[tex]\mu = np[/tex]

[tex]\mu = 260 * \frac{1}{50}[/tex]

[tex]\mu = 5.2[/tex]

Solving (b): The standard deviation

This is calculated as:

[tex]\sigma = \sqrt{\mu * (1-p)}[/tex]

[tex]\sigma = \sqrt{5.2 * (1-1/50)}[/tex]

[tex]\sigma = \sqrt{5.2 * 0.98}[/tex]

[tex]\sigma = \sqrt{5.096}[/tex]

[tex]\sigma = 2.257[/tex]

Answer:

0.9936 = 99.36% probability that during a​ year, you can avoid catastrophe with at least one working​ drive

Step-by-step explanation:

For each disk, there are only two possible outcomes. Either it works, or it does not. The probability of a disk working is independent of any other disk, which means that the binomial probability distribution is used to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

In which [tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.

[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]

And p is the probability of X happening.

Assume that there is a 8​% rate of disk drive failure in a year.

So 100 - 8 = 92% probability of working, which means that [tex]p = 0.92[/tex]

Two disks are used:

This means that [tex]n = 2[/tex]

What is the probability that during a​ year, you can avoid catastrophe with at least one working​ drive?

This is:

[tex]P(X \geq 1) = 1 - P(X = 0)[/tex]

In which

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]P(X = 0) = C_{2,0}.(0.92)^{0}.(0.08)^{2} = 0.0064[/tex]

[tex]P(X \geq 1) = 1 - P(X = 0) = 1 - 0.0064 = 0.9936[/tex]

0.9936 = 99.36% probability that during a​ year, you can avoid catastrophe with at least one working​ drive

Answer:

y = -2(x + 3)² + 2

y = 2{ -(x + 3)²+ 1}

y = 2{ -(x² + 6x + 9) + 1}

y = 2{ -x² - 6x - 9 + 1}

y = 2{ -x² - 6x - 8 }

y = -2 { x² + 6x + 8}

OR

y = -2{(x + 4)(x + 2)}

Answer:

a) 0.000016 = 0.0016% probability of selecting and finding that all three bags are overweight.

b) 0.729 = 72.9% probability of selecting and finding that all three bags are satisfactory

Step-by-step explanation:

The condition of the bags in the sample is independent of the other bags, which means that the binomial probability distribution is used to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

In which [tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.

[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]

And p is the probability of X happening.

a) What is the probability of selecting and finding that all three bags are overweight?

2.5% are overweight, which means that [tex]p = 0.025[/tex]

3 bags means that [tex]n = 3[/tex]

This probability is P(X = 3). So

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]P(X = 3) = C_{3,3}.(0.025)^{3}.(0.975)^{0} = 0.000016[/tex]

0.000016 = 0.0016% probability of selecting and finding that all three bags are overweight.

b) What is the probability of selecting and finding that all three bags are satisfactory?

90% are satisfactory, which means that [tex]p = 0.9[/tex]

3 bags means that [tex]n = 3[/tex]

This probability is P(X = 3). So

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]P(X = 3) = C_{3,3}.(0.9)^{3}.(0.1)^{0} = 0.729[/tex]

0.729 = 72.9% probability of selecting and finding that all three bags are satisfactory

Answer:

Step-by-step explanation:

Answer:

(a)So, there are 2 kings in red- one of hearts and the other of diamonds. Therefore, the probability of selecting a red king from a deck of cards= 2/52 or 1/26.

(b) There are 6 red face cards in a 52-card deck (so 46 other cards). PROBABILITIES compare the number of favorable outcomes to the total number of possible outcomes: The PROBABILITY of getting a red face card is 6/52 = 3/26.

The odds in favor of getting a red king will be 1/26. And the odds against getting a red king will be 25/26.

Its basic premise is that something will almost certainly happen. The percentage of favorable events to the total number of occurrences.

You are dealt one card from a 52-card deck.

Total events = 52

The odds in favor of getting a red king will be

Favorable events = 2

Then the probability will be

P = 2/52

P = 1/26

The odds against getting a red king will be

q = 1 – P

q = 1 – 1/26

q = 25/26

More about the probability link is given below.

https://brainly.com/question/795909

#SPJ2

Answer:b

Step-by-step explanation:

Answer:

just be smart trust me u dont need us to give u the answer ur super smart

Step-by-step explanation:

make me brainliest to help people be encourage