The lifetime of a certain brand of battery is normally distributed with a mean value of 8 hr and a standard deviation of 0.8 hr when it is used in a particular cassette player.Suppose that two new batteries are independently selected and put into the player. The player ceases to function as soon as one of the batteries fails.
(a) What is the probability that the player functions for at least 6 hr?
(b) What is the probability that the cassette player works for at most 9 hr?

Answer:

135

Step-by-step explanation:

you need to explain the actual question and not put an image without context

Answer:

angle a = 70

angle b = 45

angle c = 65

Step-by-step explanation:

Now we will try to find the measure of the unknown angle together. Starting with angle b.

Angle b and 135 make a 180 angle together therefore the following expression.

angle b + 135 = 180

b = 45

Now that we have angle be we can try to find angle a. As we know, vertical angles are always equal to one another. Angle a and 70 are vertical to each other.

a = 70

Now that we have angle a and b we can finally find c. A triangle is the a sum of 180 degrees so, a + b + c = 180

70 + 45 + c + 180

c = 65

Answer:

(8x9)^4

Step-by-step explanation: i am 99% sure

Answer:

72^4=26873856

Step-by-step explanation:

Answer:

22000

to the test

Answer:

8/24 (eight hours at school out of 24 hours of the day)

0.33 (divide 8 by 24)

33.33% (move the decimal to the right twice.)

I hope that makes sense. If you need more explanation please just comment on this and i will edit it to add what you need. Or i will just comment back. It depends.

The portion of the weekday spent at school as a fraction, a decimal and a percent can be represented as 1/3 or 0.333 or 33.3% respectively.

Fractions are type of numbers which are written in the form p/q, which implies that p parts in a whole of q.

Here p, called the numerator and q, called the denominator, are real numbers.

Given that,

You spend 8 hours each weekday at school.

Total hours in a day = 24 hours

Fraction of the hours spent = 8/24 = 1/3

Decimal of the hours spent = 0.333

Percent of the hours spent = 0.333 × 100 = 33.3%

Hence the portion of a weekday spent at school is 1/3.

Learn more about Fractions here :

https://brainly.com/question/12715980

#SPJ3

Answer:

57.3

Step-by-step explanation:

just took the quiz

Answer:

=22n+13

Let's simplify step-by-step:

21n+15+n−2

=21n+15+n+−2

Combine Like Terms:

=21n+15+n+−2

=(21n+n)+(15+−2)

=22n+13

Answer:

=22n+13

Answer:

$21

Step-by-step explanation:

There are two ways to do this question:

1. Multiply 60 by .65 and minus the product from the original price ($60)

2. Multiply 60 by .35 (This is because the discounted price maintains 35% of the regular price)

Let's do it both ways:

1. (60)(.65) = 39

60 - 39 = 21

2. (60)(.35) = 21

Therefore, the price now is $21.

I hope this helps!!

- Kay :)

Answer:

$21.00

Step-by-step explanation:

$60.00*(1.00-.65)

$60.00*(35)

$21.00

Answer:

A) (1 s, 2.3 s)

B) (-4 m/s², 3.8 m/s²)

Step-by-step explanation:

The car's position which is the distance is given by the equation;

s(t) = t³ - 5t² + 7t

A) Velocity is the first derivative of the distance. Thus;

v(t) = ds/dt = 3t² - 10t + 7

At v = 0, we have;

3t² - 10t + 7 = 0

Using quadratic formula, we have;

t = 1 and t = 2.3

Thus, time at velocity of 0 is t = (1 s, 2.3 s)

B) acceleration is the derivative of the velocity. Thus;

a(t) = dV/dt = 6t - 10

At velocity of 0, we got t = 1 and t = 2.3

Thus;

a(1) = 6(1) - 10 = -4 m/s²

a(2.3) = 6(2.3) - 10 = 3.8 m/s

Thus, a(t) at v = 0 gives; (-4 m/s², 3.8 m/s²)

Let f(x) = ax ² + bx + c. Then

f '(x) = 2ax + b

f ''(x) = 2a

f (-3) = -18, so

9a - 3b + c = -18

f ' (-3) = 16, so

-6a + b = 16

f '' (-3) = -6, so

2a = -6

Then a = -3, b = -2, and c = 3, so that

f(x) = -3x ² - 2x + 3

Answer:

25 cups of apple juice and 10 cups of sparking water.

Step-by-step explanation:

E 10 12

x=18*5)14. x=40/4. x=10. y=(15*4)/5 y=60/5 y=12.

resposta : 10 e 12

Answer:

81

Step-by-step explanation:

25 and 27 are not perfect squares so they can not be the answer.

36 and 81 are both multiples of 3, but only 81 is not even, so the answer is 81

Answer:

-no solution-

Step-by-step explanation:

Let's solve your system by elimination.

−6x+2y=−14;−9x+3y=−21

Multiply the first equation by 3,and multiply the second equation by -2.

3(−6x+2y=−14)

−2(−9x+3y=−21)

Becomes:

−18x+6y=−42

18x−6y=42

Add these equations to eliminate y:

0=0

Answer:

Infinitely many solutions.

Let's solve your system by substitution.

−6x+2y=−14;−9x+3y=−21

Step: Solve−6x+2y=−14for x:

−6x+2y=−14

−6x+2y+−2y=−14+−2y(Add -2y to both sides)

−6x=−2y−14

−6x

−6

=

−2y−14

−6

(Divide both sides by -6)

x=

1

3

y+

7

3

Step: Substitute

1

3

y+

7

3

forxin−9x+3y=−21:

−9x+3y=−21

−9(

1

3

y+

7

3

)+3y=−21

−21=−21(Simplify both sides of the equation)

−21+21=−21+21(Add 21 to both sides)

0=0

Answer:

Infinitely many solutions.

If you divide first equation by two and the second by three they are both the same line so there are infinitely many solutions.

Answer:

680 girls and 850 boys

Step-by-step explanation:

the ratio of girls is 4/9

then we can find the number of girls (G) in the group of 1530 students using proportions:

4 / 9 = G / 1530

solving for G by multiplying both sides of the proportion by 1530, we get:

G = 4 * 1530 / 9 = 680

So there were:

680 girls and 1530 - 680 = 850 boys

Answer:

the answer will be

girls 680

boys 850

Answer:

Emily because Lindsay is at the movies so she can't ride the Ferris Wheel. Janelle is too afraid to go that high. Emily only doesn't like caramel apples so she can still go on the Ferris Wheel.

Answer:

Emily

Step-by-step explanation:

The third person riding on the ferris wheel is Emily. why? well Lindsey is at the movies so she can't be at the carnival riding the ferris weel, Janelle is afraid of heights so their is no way she would ride the ferris wheel, but Emily just doesn't like Carmel apples which would not stop her from riding the ferris wheel.

Answer:

4x+9y-36=0

Step-by-step explanation:

Use the slope-intercept form  

y

=

m

x

+

b

 to find the slope  

m

and y-intercept  

b

.

Slope:  

−

4

9

y-intercept:  

(

0

,

4

)

Answer:

there is a 60% chance they pick a blue pencil

Answer:

Step-by-step explanation:

There are 6 friends total and for them to make $45 each, you would need to multiply 6 to 45.  The only way you could do this is if you have a fraction supporting the variable.

1/6x = 45

~Multiply 6 to both sides

x = 270

Best of Luck!

Answer:

[tex]\huge\boxed{\$ 270}[/tex]

Step-by-step explanation:

We can break this problem down to understand it.

Chad and his friend make an unknown amount of money while selling t-shirts. We'll assign this to a variable, [tex]x[/tex].

After splitting it amongst him and his 5 friends, he wants everyone to have $45.

Therefore, we can multiply the profit per person by the number of people to find how much money has to be made in total.

Chad + 5 people = 6 people

We can write an equation for this problem.

[tex]\displaystyle \frac{1}{6}x=45[/tex]

To solve this, we multiply both sides by 6 to cancel out the [tex]\frac{1}{6}[/tex] (as [tex]\frac{1}{6} \cdot 6 = 1[/tex]).

[tex]45 \cdot 6 = 270[/tex]

Hope this helped!

Answer:

Step-by-step explanation:

Mean of four numbers a, b, c, and d is 8:

Mean of seven numbers x, y, z, a, b, c and d is 12:

Substitute the sum of 4 numbers:

Mean of x, y and z is:

Answer:

89

Step-by-step explanation:

6x7=42

42+47=89

Answer:

you have 89 marbles

Step-by-step explanation:

basically it's addition and multiplication. All you needed is a piece of paper and a pencil.It'll help:)

Answer: -1

Step-by-step explanation:

First change tan(315) to:

[tex]\frac{\sin(315)}{\cos(315)}[/tex]

Then evaluate the sine and cosine function. What is the y component of 315 degrees? What is the x component of 315 degrees?

[tex]-\frac{\sqrt{2} }{2} /\frac{\sqrt{2} }{2} =-1[/tex]

Answer:

300

Step-by-step explanation:

9514 1404 393

Answer:

  (a) not proportional

  (b) k = 7/8

Step-by-step explanation:

When a linear equation is of the form ...

  y = mx + b

with b ≠ 0, the relation is NOT PROPORTIONAL.

__

If b=0, so the equation is of the form ...

  y = kx

then the relation IS PROPORTIONAL. The constant of proportionality is k.

__

(a) Not proportional

(b) Proportional with k = 7/8

Answer:

-2x-8

2x= -8

x = -4

or

( x - 2 )(x + 2 )

x=2

x= -2

Answer:

It's asking what numbers (or integers) will equal to the number given. so it could be any four numbers that will give you 2174 exactly

Step-by-step explanation:

If this doesn't simplify it enough, let me know

Answer:

Here's your answer.......

.......

Answer:

412 is not divisible by 3

Answer:

Is 412 divisible by 3?

No

1235453340 is divisible by 2, 4 and 10

Yes

Step-by-step explanation:

Answer:

0.7881 = 78.81% probability that a randomly chosen Ford truck outperforms a randomly chosen GM truck in terms of fuel efficiency

Step-by-step explanation:

When the distribution is normal, we use the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

Subtraction of normal variables:

When we subtract normal variables, the mean is the subtraction of the means, and the standard deviation is the square root of the sum of the variances.

The fuel efficiency of Ford trucks is found to follow a normal distribution with mean 20 mpg and a standard deviation of 3 mpg.

This means that [tex]\mu_{F} = 20, \sigma_{F} = 3[/tex]

The fuel efficiency of GM trucks is found to follow a normal distribution with mean 24 mpg and standard deviation of 4 mpg.

This means that [tex]\mu_{G} = 24, \sigma_{G} = 4[/tex]

Compute the probability that a randomly chosen Ford truck outperforms a randomly chosen GM truck in terms of fuel efficiency

This is the probability that the subtraction of ford by gm is less than 0. First, we find the mean and the standard deviation.

[tex]\mu = \mu_{F} - \mu_{G} = 20 - 24 = -4[/tex]

[tex]\sigma = \sqrt{\sigma_{F}^2+\sigma_{G}^2} = \sqrt{3^2+4^2} = 5[/tex]

This probability is the pvalue of Z when X = 0. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{0 - (-4)}{5}[/tex]

[tex]Z = 0.8[/tex]

[tex]Z = 0.8[/tex] has a pvalue of 0.7881

0.7881 = 78.81% probability that a randomly chosen Ford truck outperforms a randomly chosen GM truck in terms of fuel efficiency