A system consisting of one original unit plus a spare can function for a random amount of time X. If the density of Xis given (in units of months) byf(x) ={cxe -x/2 x>0 0 x<0 What is the probability that the system functions for at least 5 months?

Answer:

Option C: 0.7734

Step-by-step explanation:

From z-distribution table attached,

P(Z ≤ -0.75) = 0.2266

However, we are looking for proportion of observations from a standard Normal distribution that take values larger than -0.75.

Thus;

P(Z > -0.75) = P(Z ≤ 0.75) = 1 - 0.2266

P(Z > -0.75) = 0.7734

Option C is the correct answer.

Answer:

First multiply each brackets

90-60

30

Step-by-step explanation:

Answer:

9 x 3= 27 and 30 + 30=  60.. so 60- 27= 33, but if you want to do 27- 30.. it would be -33.

Step-by-step explanation:

Hope that answers your question!

Answer:

B

Step-by-step explanation:

x=√7

squaring

x²=7

Answer:

the answer is b

Step-by-step explanation:

Answer:

1.4 inches.

Step-by-step explanation:

Given that the length of the pool = 200 ft.

Scale factor = 1725.

As,

[tex]\text{Scale factor }=\frac{\text{Original length}}{\text{Scaled length}}[/tex]

So,

[tex]\text{Scaled length} = \frac{\text{Original length}}{\text{Scale factor}}[/tex]

By using the given values, we have

{Scaled length} [tex]= \frac{200}{1725} ft.=0.116 ft.[/tex]

As 1 foot = 12 inch,

So, scaled length = 0.116 x 12 = 1.4 inches.

Hence, the scale length of the model = 1.4 inches.

Answer:

5

Step-by-step explanation:

12 x - 3y / 4 x - Z

=12×3-3×1/3÷4×3-5

=36-1/12-5

=35/7

=5

So the final answer is 5.

Step-by-step explanation:

1.

the null hypothesis:

H0: u = 8 hours ( new Yorkers sleep for 8 hours)

The alternate hypothesis;

H1: u ≠ 8 hours ( new Yorkers sleep less than 8 hours)

b.

test statistic

t = (barX - u)/s/√n

= 7.73-8/0.77/√25

= -1.7532

degree of freedom = n-1

= 25-1 = 24

c.

p(value)

= p(t < -1.7532)

= 0.046

obviously we can see that the p value is less than 0.05 alpha level so we reject the null hypothesis.

d

The data gives strong evidence that new Yorkers sleep less than 8 hours on average every night.

e.

at 90% level of confidence

we have

7.73-0.26334, 7.73+0.26334

= 7.466, 7.993

please check attachment

thank you!

Answer:

The equation is likely (x2 -2x -3)/(x+2) and to simplify you can do polynomial synthetic division or long division. Using long division because it works in all cases:

       ________

x+2√x2 -2x -3             how many times does x go into x2  , x times

       x - 4 ______

x+2√x2  - 2x -3            multiply x by x + 2 and create the next row

     -(x2 )

          -4x - 3             bring down the -3 and repeat first step. how many times does x go into -4x, -4 times

        -(-4x - 8)            multiply x + 2 by -4

                   5             (this is the remainder but it must be in the form 5/(x+2)

so the answer is x - 4 + 5/(x + 2). Hopefully, this is what your teacher considers "simplified".

Step-by-step explanation:

Copied this from wyzant.com.  

Answer: 49

see below for work

Answer:

gang gang

Step-by-step explanation:

Answer:

5: c=65  d=125  e=60

6: c= 58 d= 121 e=63

7. a=55 b=64 c=61

8. a=61 b=55 c=64

Step-by-step explanation: :)

Answer:

= h^-6

Step-by-step explanation:

When dividing powers you subtract them (indices rules)

--> -2 - 4 = -6

Hope this helps, please mark as brainliest

Answer:

0.0520833333 is the answer

Answer:

0.05208333333 (reoccurring)

Step-by-step explanation:

Simple bus stop division (:

Answer:

2). 79°; 3). 65°; 4). 45°; 5) 73°

Step-by-step explanation:

m∠4 = 180° - (70° + 65°) = 45°

m∠3 = 180° - (45° + 70°) = 65°

m∠2 + m∠3 = 180° - 36° = 144°

m∠2 = 144° - 65° = 79°

m∠5 = 118° - m∠4 = 118° - 45° = 73°

Answer:

First, make the denominators

15/2+2/2

Then, add

17/2

If you want it in decimal points

8.5

Step-by-step explanation:

I hope I explained well, please give me brainliest

Answer:

195

Step-by-step explanation:

you just muliply

Answer:

The answer is 175! :)

I recommend searching or creating a times table for yourself, they are incredibly handy! Easy to print off or write down. :))

Step-by-step explanation:

Answer:

I dont know im in middle school can you please giva me one i have to get my grades up

Step-by-step explanation:

Answer:

A.

Step-by-step explanation:

3

5

(1)

4

(25)

=

3

5

4

(25)

=

3

20

(25)

=

15

4

Answer: Three-8 ounce containers

Step-by-step explanation: 3 x 1.29 divided by 0.6= $6.45 for three 8-ounce containers

4 x 3.77 divided by 0.6= $15.08

Answer:

138 and 210?

Step-by-step explanation:

-3a-4(a-6)=24-7a

-3a-4a+24=24-7a

-7a+24=24-7a

-7a+24=-7a+24

-7a+24-24=-7a+24-24

Simplify

Subtract the numbers

Subtract the numbers

−7a=-7a

Add 7a to both sides of the equation

-7a+7a =-7a+7a

Simplify

Combine like terms

Combine like terms

0=0

answer is 0=0

The answer is D.) OP≅OQ

I hope this is the right graph

Answer:

= 59 - (59*0.07)

= 59 - 4.13

= 54.87

Answer:

The result would be 54.87

Answer: 98

Step-by-step explanation:

Formula to find sample size if population standard deviation is known:

[tex]n=(\dfrac{z^c\times\sigma}{E})^2[/tex] , where [tex]\sigma=[/tex]population standard deviation, [tex]z^c[/tex] =Critical z-value for confidence level, E= Margin of error.

Given: [tex]\sigma=30,\ \ \ E=10[/tex]

Critical z-value for 90% confidence = 1.645

[tex]n=(\dfrac{1.645\times60}{10})^2\\\\=(1.645\times6)^2\\\\=9.87^2\\\\=97.4169\approx98[/tex]

Required minimum sample size = 98

Answer:

C

Step-by-step explanation:

y=mx+n m is slope if slopes are perpendicular m1.m2=-1

(2/3) . (-3/2) = -1

m1=2/3

m2=-3/2

y=(2/3)x-3 m=2/3 n= -3

y=(-3/2)x+2   m = -3/2 n = 2