The shape of the distribution of the time required to get an oil change at a 15-minute oil-change facility is unknown. However, records indicate that the mean time is 16.2 minutes, and the standard deviation is 3.4 minutes.

Requried:
a. What is the probabilty that a random sample of n = 40 oil changes results in a sample mean time less than 15 minutes?
b. Suppose the manager agrees to pay each employee a​ $50 bonus if they meet a certain goal. On a typical​ Saturday, the​ oil-change facility will perform 40 oil changes between 10 A.M. and 12 P.M. Treating this as a random​ sample, there
would be a​ 10% chance of the mean​ oil-change time being at or below what​ value? This will be the goal established by the manager.

Answer:

Increasing: [tex](0, 750)[/tex]

Decreasing: [tex](750, \infty)[/tex]

Step-by-step explanation:

Critical points:

The critical points of a function f(x) are the values of x for which:

[tex]f'(x) = 0[/tex]

For any value of x, if f'(x) > 0, the function is increasing. Otherwise, if f'(x) < 0, the function is decreasing.

The critical points help us find these intervals.

In this question:

[tex]P(x) = -0.004x^{2} + 6x - 5000[/tex]

So

[tex]P'(x) = -0.008x + 6[/tex]

Critical point:

[tex]P'(x) = 0[/tex]

[tex]-0.008x + 6 = 0[/tex]

[tex]0.008x = 6[/tex]

[tex]x = \frac{6}{0.008}[/tex]

[tex]x = 750[/tex]

We have two intervals:

(0, 750) and [tex](750, \infty)[/tex]

(0, 750)

Will find P'(x) when x = 1

[tex]P'(x) = -0.008x + 6 = -0.008*1 + 6 = 5.992[/tex]

Positive, so increasing.

Interval [tex](750, \infty)[/tex]

Will find P'(x) when x = 800

[tex]P'(x) = -0.008x + 6 = -0.008*800 + 6 = -0.4[/tex]

Negative, then decreasing.

Answer:

Increasing: [tex](0, 750)[/tex]

Decreasing: [tex](750, \infty)[/tex]

Answer:

Step-by-step explanation:

The equivalent between sets is determined by the number of elements. If two sets have the same number of elements, then they are equivalent sets.

In this case, a year has 12 months, and the US has 50 states. So, one month is not equal to 1 state because they have different natures and they represent a different proportion. A month represents 1/12 of a year and a state represents 1/50 of the total number of states.

Answer:

x=12.5

Step-by-step explanation:

0.7x times (-1.4)=-3.5

-0.28x=-3.5 (divide both sides)

Ans:12.5

Answer:

20

Step-by-step explanation:

fist you convert 6l to ml=6×1000

then,300/300:6000/300

gives you 1:20

Answer:

6.5 ft

Step-by-step explanation:

When we draw out our picture of our triangle and label our givens, we should see that we need to use cos∅:

cos57° = x/12

12cos57° = x

x = 6.53567 ft

Answer:L=30 S=50

Step-by-step explanation:

3.25 x 50 = 162.5

245 - 162.5 = 82.5

82.5 divided by 30 equals 2.75.

Answer:

perimeter = 12 miles

area = 6 square miles

Step-by-step explanation:

Since it makes a right triangle, use the Pythagorean Formula.

3^2+4^2=c^2

9+16=c^2

25=c^2

5=c, so the hypotenuse of the right triangle is 5.

Perimeter = 3+4+5 = 12 miles

area = 1/2bh (1/2 base times height)

=1/2x3x4

=6

Area = 6 square miles

Answer:

y + 1 = 3x

Step-by-step explanation:

In order for there to be an infinite number of solutions, the two lines need to be the same.

y+1 = 3x

y=3x-1 are both the same

Answer:

a)y + 1 = 3x

Step-by-step explanation:

Answer:

it we'll be 0.3

Step-by-step explanation:

trust me man I like to explain but it's long

Answer:

0.3 meter or 3/10 meter

Step-by-step explanation:

As there are 100cm in 1 meter and you want to find 30cm in terms of meters.

It will be as

100cm = 1 meter     (rule/lax)

100/100 cm = 1/100  meter   (divide both sides of equation with 100)

1 cm = 1/100 meter

1 *30 cm = (1/100)*30  meter    (multiply both sides with 30)

30 cm = 30/100 meter

30/100 more shortly can be written as  3/10 meter or in decimals 0.3 meter.

Answer:

D

Step-by-step explanation:

Solution:-

The standard sinusoidal waveform defined over the domain [ 0 , 2π ] is given as:

                                   f ( x ) = sin ( w*x ± k ) ± b

Where,

                 w: The frequency of the cycle

                 k: The phase difference

                 b: The vertical shift of center line from origin

We are given that the function completes 2 cycles over the domain of [ 0 , 2π ]. The number of cycles of a sinusoidal wave is given by the frequency parameter ( w ).

We will plug in w = 2. No information is given regarding the phase difference ( k ) and the position of waveform from the origin. So we can set these parameters to zero. k = b = 0.

The resulting sinusoidal waveform can be expressed as:

                           f ( x ) = sin ( 2x )  ... Answer

Answer:

24

Step-by-step explanation:

Answer:

rhombus

Step-by-step explanation:

on edge

Answer:

0.007

Step-by-step explanation:

We were told in the above question that a random sample of 51 households is monitored for one year to determine aluminum usage

Step 1

We would have to find the sample standard deviation.

We use the formula = σ/√n

σ = 12.2 pounds

n = number of house holds = 51

= 12.2/√51

Sample Standard deviation = 1.7083417025.

Step 2

We find the z score for when the sample mean is more than 61

z-score formula is z = (x-μ)/σ

where:

x = raw score = 61 pounds

μ = the population mean = 56.8 pounds

σ = the sample standard deviation = 1.7083417025

z = (x-μ)/σ

z = (61 - 56.8)/ 1.7083417025

z = 2.45852

Finding the Probability using the z score table

P(z = 2.45852) = 0.99302

P(x>61) = 1 - P(z = 2.45852) = 0.0069755

≈ 0.007

Therefore,the probability that the sample mean will be more than 61 pounds is 0.007

Answer:

The depreciated value of the car after 1 yr is ​$16,353

The depreciated value of the car after 2 yr is ​$12,264.75

Step-by-step explanation:

Given

purchase amount P= $21,804

rate of depreciation R= 25%

applying the formula for the car deprecation we have

[tex]A= P*(1-\frac{R}{100} )^n[/tex]

Where,

A is the value of the car after n years,

P is the purchase amount,

R is the percentage rate of depreciation per annum,

n is the number of years after the purchase.

1. The depreciated value of the car after 1 yr is ​

n=1

[tex]A= 21,804*(1-\frac{25}{100} )^1\\\\A= 21,804*(1-0.25 )^1\\\\A= 21,804*0.75\\\\A= 16353[/tex]

The depreciated value of the car after 1 yr is ​$16,353

2. The depreciated value of the car after 2 yr is ​

n=2

[tex]A= 21,804*(1-\frac{25}{100} )^2\\\\A= 21,804*(1-0.25 )^2\\\\A= 21,804*0.75^2\\\\A= 21,804*0.5625\\\\A= 12264.75[/tex]

The depreciated value of the car after 2 yr is ​$12,264.75

Answer:

(x + 8)² + (y - 3)² = 64

Step-by-step explanation:

The equation of a circle in standard form is

(x - h)² + (y - k)² = r²

where (h, k) are the coordinates of the centre and r is the radius

Here (h, k) = (- 8, 3) and r = 8 , thus

(x - (- 8))² + (y - 3)² = 8² , that is

(x + 8)² + (y - 3)² = 64

Answer:

See below.

Step-by-step explanation:

The equation for a circle is:

[tex](x-h)^2+(y-k)^2=r^2[/tex], where (h,k) is the center and r is the radius.

Plug in what we know. (-8,3) for (h,k) respectively and 8 for the radius:

[tex](x-(-8))^2+(y-(3))^2=(8)^2[/tex]

[tex](x+8)^2+(y-3)^2=64[/tex]

median=order them and find the middle=6

mean=add them all up and divide by the amount of numbers=(3+6+9+7+4+6+7+0 +7)/9=5.4

range= the difference between the smallest and largest number=9-3=6

mode= the one that appears the most= 7

The median, mean, range and mode will be 6, 5.4, 9 and 7.

The median is the number in the middle when arranged in an ascending order. The numbers will be:

0, 3, 4, 6, 6, 7, 7, 7, 9.

The median is 6.

The range is the difference between the highest and lowest number which is: = 9 - 0 = 9

The mode is the number that appears most which is 7.

The mean will be the average which will be:

= (0 + 3 + 4 + 6 + 6 + 7 + 7 + 7 + 9) / 9.

= 49/9

= 5.4

Read related link on:

https://brainly.com/question/9426296

The required 90% confidence interval for adult males is

[tex]\text {CI} = (64.2, \: 70.6)\\\\[/tex]

The required 90% confidence interval for adult females is

[tex]\text {CI} = (72, \: 79.2)\\\\[/tex]

The confidence interval of male and female pulse rates do not overlap since the mean pulse rate of female is way greater than the mean pulse rate of males.

Step-by-step explanation:

We are given the pulse rates of adult females and adult males and we have to construct the 90% confidence interval of the mean pulse rate for males and females.

Let us first compute the mean and standard deviation of the given pulse rates data.

Using Excel,  

=AVERAGE(number1, number2,....)  

The mean pulse rate of adult males is found to be

[tex]\bar{x}_{male} = 67.4[/tex]

The mean pulse rate of adult females is found to be

[tex]\bar{x}_{female} = 75.6[/tex]

Using Excel,  

=STDEV(number1, number2,....)    

The standard deviation for adult male pulse rate is found to be

 [tex]s_{male} = 11.9[/tex]

The standard deviation for adult female pulse rate is found to be  

 [tex]s_{female} = 13.5[/tex]

The confidence interval is given by

[tex]$ \text {CI} = \bar{x} \pm t_{\alpha/2}(\frac{s}{\sqrt{n} } ) $\\\\[/tex]

Where [tex]\bar{x}[/tex] is the sample mean, n is the sample size, s is the sample standard deviation and   [tex]t_{\alpha/2}[/tex] is the t-score corresponding to a 90% confidence level.  

The t-score corresponding to a 90% confidence level is  

Significance level = α = 1 - 0.90 = 0.10/2 = 0.05  

Degree of freedom = n - 1 = 40 - 1 = 39

From the t-table at α = 0.05 and DoF = 39

t-score =  1.685

The required 90% confidence interval for adult males is

[tex]\text {CI} = 67.4 \pm 1.685\cdot \frac{11.9}{\sqrt{40} } \\\\\text {CI} = 67.4 \pm 1.685\cdot 1.882\\\\\text {CI} = 67.4 \pm 3.17\\\\\text {CI} = 67.4 - 3.17, \: 67.4 + 3.17\\\\\text {CI} = (64.2, \: 70.6)\\\\[/tex]

Therefore, we are 90% confident that the actual mean pulse rate of adult male is within the range of 64.2 to 70.6 bpm

The required 90% confidence interval for adult females is

[tex]\text {CI} = 75.6 \pm 1.685\cdot \frac{13.5}{\sqrt{40} } \\\\\text {CI} = 75.6 \pm 1.685\cdot 2.1345\\\\\text {CI} = 75.6 \pm 3.60\\\\\text {CI} = 75.6 - 3.60, \: 75.6 + 3.60\\\\\text {CI} = (72, \: 79.2)\\\\[/tex]

Therefore, we are 90% confident that the actual mean pulse rate of adult female is within the range of 72 to 79.2 bpm

Comparison:

The confidence interval of male and female pulse rates do not overlap since the mean pulse rate of female is way greater than the mean pulse rate of males.

Answer:

C and D

Step-by-step explanation:

khan acedemy

An equation is formed when two equal expressions. The solutions to the given equation are A, B, and C.

An equation is formed when two equal expressions are equated together with the help of an equal sign '='.

The solution of the given equation v²=25/81 can be found as shown below.

v²=25/81

Taking the square root of both sides of the equation,

√(v²) = √(25/81)

v = √(25/81)

v = √(5² / 9²)

v = ± 5/9

Hence, the solutions of the given equation are A, B, and C.

Learn more about Equation here:

https://brainly.com/question/2263981

#SPJ2

Answer:

The 90% onfidence interval for the mean number of cans that all of the families in the city recycle per month is between 129.34 and 150.66 cans per month

Step-by-step explanation:

We have the standard deviation of the sample, so we use the t-distribution to solve this question.

The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So

df = 18 - 1 = 17

90% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 17 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.9}{2} = 0.95[/tex]. So we have T = 1.74

The margin of error is:

[tex]M = T\frac{s}{\sqrt{n}} = 1.74\frac{26}{\sqrt{18}} = 10.66[/tex]

In which s is the standard deviation of the sample and n is the size of the sample.

The lower end of the interval is the sample mean subtracted by M. So it is 140 - 10.66 = 129.34 cans per month

The upper end of the interval is the sample mean added to M. So it is 140 + 10.66 = 150.66 cans per month.

The 90% onfidence interval for the mean number of cans that all of the families in the city recycle per month is between 129.34 and 150.66 cans per month

Multiply price per pound by total pounds:

2.50 x 3.5 = 8.75

Total cost = $8.75

Answer:

The cost is $8.75  for 3.5 lbs

Step-by-step explanation:

The rate is 2.50 per pound

Multiply the number of pounds by the rate

3.5 * 2.50 =8.75

The cost is $8.75  for 3.5 lbs

Answer:

.7698

Step-by-step explanation:

Answer:

a. 0.34885

b. 0.04651

c. 0.02404

d. 36

e. 14.7, say 15 trials

Step-by-step explanation:

Q17070205

Note:  

1. In order to be applicable to established probability distributions, each roll is considered a Bernouilli trial, i.e. has only two outcomes, success or failure, and are all independent of each other.

2. use R to find the probability values from the respective distributions.

a) the chance that the first 6 appears before the tenth roll

This means that a six appears exactly once between the first and the nineth roll.

Using binomial distribution, p=1/6, n=9, x=1

dbinom(1,9,1/6) = 0.34885

b) the chance that the third 6 appears on the tenth roll

This means exactly two six's appear between the first and 9th rolls, and the tenth roll is a six.

Again, we have a binomial distribution of p=1/6, n=9, x=2

p1 = dbinom(2,9,1/6) = 0.27908

The probability of the tenth roll being a 6 is, evidently, p2 = 1/6.

Thus the probability of both happening, by the multiplication rule, assuming independence  

P(third on the tenth roll) = p1*p2 = 0.04651

c) the chance of seeing three 6's among the first ten rolls given that there were six 6's among the first twenty roles.

Again, using binomial distribution, probability of 3-6's in the first 10 rolls,

p1 = dbinom(3,10,1/6) = 0.15504

Probability of 3-6's in the NEXT 10 rolls

p1 = dbinom(3,10,1/6) = 0.15504

Probability of both happening  (multiplication rule, assuming both events are independent)

= p1 *  p1 = 0.02404

d) the expected number of rolls until six 6's appear

Using the negative binomial distribution, the expected number of failures before n=6 successes, with probability p = 1/6

=  n(1-p)/p

Total number of rolls by adding n  

= n(1-p)/p + n = n(1-p+p)/p = n/p = 6/(1/6) = 36

e) the expected number of rolls until all six faces appear

P1 = 6/6 because the firs trial (roll) can be any face with probability 1

P2 = 6/5 because the second trial for a different face has probability 5/6, so requires 6/5 trials

P3 = 6/4 ...

P4 = 6/3

P5 = 6/2

P6 = 6/1

So the total mean (expected) number of trials is 6/6+6/5+6/4+6/3+6/2+6/1 = 14.7, say 15 trials

Answer:

100%

Step-by-step explanation:

Start with x.

x = x/1

Increase the numerator by 60% to 1.6x.

Decrease the numerator by 20% to 0.8.

The new fraction is

1.6x/0.8

Do the division.

1.6x/0.8 = 2x

The fraction increased from x to 2x. It became double of what it was. From x to 2x, the increase is x. Since x was the original number x is 100%.

The increase is 100%.

Answer:

33%

Step-by-step explanation:

let fraction be x/y

numerator increased by 60%

=x+60%ofx

=8x

denominator increased by 20%

=y+20%of y

so the increased fraction is 4x/3y

let the fraction is increased by a%

then

x/y +a%of (x/y)=4x/3y

or, a%of(x/y)=x/3y

[tex]a\% = \frac{x}{3y} \times \frac{y}{x} [/tex]

therefore a=33

anda%=33%

Answer:

true

Step-by-step explanation:

A prism is a solid with parallelogram sides (usually rectangles) and a polygon for the 2 bases. Any polygon can be the base.

Answer:

Hello!

__________________

Your answer would be (A) True.

Step-by-step explanation: Hope this helped you!

Any polygon can be the base of a prism so the answer is true.

Answer:

  CPCTC

Step-by-step explanation:

Statements 3 and 4 show the top and bottom triangles are congruent, and the left and right triangles are congruent. Statement 5 is making use of these facts to claim that the alternate interior angles are congruent. This claim is valid because ...

  Corresponding Parts of Congruent Triangles are Congruent (CPCTC)

Answer:

50.24 yd²

Step-by-step explanation:

pi r² = (3.14)(4)² = 50.24

Answer:

x= -3, y= -5

or x= 5, y=3

Step-by-step explanation:

① Label the 2 equations

x² +y²= 34 -----(1)

3x -3y= 6 -----(2)

From (2):

x -y= 2 -----(3)

Notice that (x-y)²= x² -2xy +y²

Thus, (equation 3)²= (equation 1) -2xy

Squaring (3):

(x -y)²= 2²

(x -y)²= 4

Expand terms in bracket:

x² -2xy +y²= 4

x² +y² -2xy= 4 -----(4)

subst. (1) into (4):

34 -2xy= 4

2xy= 34 -4 (bring constant to 1 side)

2xy= 30 (simplify)

xy= 30 ÷2 (÷2 throughout)

xy= 15 -----(5)

From (3):

x= y +2 -----(6)

I'll rewrite 2 of the equations.

x= y +2 -----(6)

xy= 15 -----(5)

Subst. (6) into (5):

y(y+2)= 15

y² +2y= 15

y² +2y -15= 0

(y +5)(y -3)=0

y+5= 0 or y-3=0

y= -5 or y= 3

Subst. into (6):

x= -5 +2 or x= 3 +2

x= -3 or x= 5

Answer:

y=-5,                 y=3

x=-3.,                x=5

Step-by-step explanation:

x^2+y^2=34

3x-3y=6

isolate x in te equation

3x-3y=6

x=3/3 y+6/3

x=y+2

plug the y+2 in the equation:

x^2+y^2=34

(y+2)^2+y^2=34

y^2+4y+4+y^2=34

2y^2+4y=34-4

2y^2+4y=30 divide by 2

y^2+2x-15=0 factorize

(y+5)(y-3)=0 eiter y+5=0 ten y=-5 or y-3=0 then y=3

now plug the solution in the equation

3x-3y=6

3x-3(-5)=6

3x=6-15

x=-9/3=-3

for y=3

3x-3y=6

3x-9=6

3x=15

x=5

Answer:

21=2w+2w+3    18=4w     w=4.5

Answer:

-2n

Step-by-step explanation:

f(x)=7-2x {1,2}

f(1)=7-2(1)=5

f(2)=7-2(2)=3

Slope (m)=3/5

{7-2(1)}-{7-2(2)}=3-5=-2

In terms of n=-2n

The upper and lower sums for the region bounded by the graph of the function and the x-axis on the given interval is [5, 3]

Given the function of the graph bounded by the inteval [1, 2] expressed as

f(x) = 7 - 2x

The upper limit of the function is the point where the domain of the function x is 2. Substitute x = 2 into the function, we will have:

f(2) = 7 - 2(2)

f(2) = 7 - 4

f(2) = 3

For the lower limit, the domain of the function is at x = 2:

f(1) = 7 - 2(1)

f(1) = 7 - 2

f(1) = 5

Hence the upper and lower sums for the region bounded by the graph of the function and the x-axis on the given interval is [5, 3].

Learn more here: https://brainly.com/question/18829130

Answer:

1. continuous random variable

2. not a random variable

3. a continuous random variable

Step-by-step explanation:

The classifications are as follow

a)  The height of the player reported in the game day program is treated as a continuous random variable as these values could be determined through measuring them

b)  The color of student car is not a random variable as it does not contain any quantitative data or we can say numerical data

c)  The exact weight of the bag is a continuous variable as it is lie between the range