!NO LINKS, NO FILES!

please :)

Answer:

The margin of error is of 623.2016.

The 95% confidence interval for the true difference between average lifetimes for brakes using Compound 1 and brakes using Compound 2 is (-8546.2016, -7299.7984).

Step-by-step explanation:

Before building the confidence interval, we need to understand the central limit theorem, and subtraction between normal variables.

Central Limit Theorem

The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

Subtraction between normal variables:

When two normal variables are subtracted, the mean is the subtraction of the means while the standard deviation is the square root of the sum of the variances.

A sample of 243 brakes using Compound 1 yields an average brake life of 37,866 miles. The population standard deviation for Compound 1 is 4414 miles.

This means that [tex]\mu_1 = 37866, s_1 = \frac{4414}{\sqrt{243}} = 283.16[/tex]

A sample of 268 brakes using Compound 2 yields an average brake life of 45,789 miles. The population standard deviation for Compound 2 is 2368 miles.

This means that [tex]\mu_2 = 45789, s_2 = \frac{2368}{\sqrt{268}} = 144.65[/tex]

Distribution of the difference between average lifetimes for brakes using Compound 1 and brakes using Compound 2.

The mean is:

[tex]\mu = \mu_1 - \mu_2 = 37866 - 45789 = -7923[/tex]

The standard deviation is:

[tex]s = \sqrt{s_1^2 + s_2^2} = \sqrt{283.16^2 + 144.64^2} = 317.96[/tex]

Confidence interval:

We have that to find our [tex]\alpha[/tex] level, that is the subtraction of 1 by the confidence interval divided by 2. So:

[tex]\alpha = \frac{1 - 0.95}{2} = 0.025[/tex]

Now, we have to find z in the Ztable as such z has a pvalue of [tex]1 - \alpha[/tex].

That is z with a pvalue of [tex]1 - 0.025 = 0.975[/tex], so Z = 1.96.

Now, find the margin of error M as such

[tex]M = zs[/tex]

[tex]M = 1.96*317.96 = 623.2016[/tex]

The margin of error is of 623.2016.

The lower end of the interval is the sample mean subtracted by M. So it is -7923 - 623.2016 = -8546.2016

The upper end of the interval is the sample mean added to M. So it is -7923 + 623.2016 = -7299.7984

The 95% confidence interval for the true difference between average lifetimes for brakes using Compound 1 and brakes using Compound 2 is (-8546.2016, -7299.7984).

Answer:

hope you can now substitute and find y

Answer:

C

Step-by-step explanation:

Aaron received four stamps. He already had eight times as much. 32 + 4. Before pasting the stamps into albums, Aaron divides them equally into three envelopes. (32 + 4) ÷ 3.

Answer:

-4

Step-by-step explanation:

Answer:

-22

Step-by-step explanation:

-13 - 9

When both the numbers have the same sign, we add them. After adding we put the same sign of the numbers to the answer

Answer:

a9 = 26

Step-by-step explanation:

nth term of an arithmetic sequence an = a + (n-1)d

a16 = a+15d = 12.... 1

a7 = a+6d = 30.....2

Subtract

15d - 6d = 12 - 30

9d = -18

d =-18/9

d = -2

Substitute d = -2 into 1

a + 15d = 12

a+15(-2) = 12

a - 30 = 12

a = 12 + 30

a = 42

Get a9;

a9 = a+8d

a9 = 42+8(-2)

a9 = 42 - 16

a9 = 26

hence the 9th term of the sequence is 26

Answer:

The calculated test  |Z| = |-1.55| >1.405 at 0.08 level of significance

The null hypothesis is rejected at a 0.08 level of significance.

An Alternative hypothesis is accepted

A light bulb manufacturer guarantees that the mean life of a certain type of light bulb is at most 754 hour

Step-by-step explanation:

Step(i):-

Given that the mean life of a certain type of light bulb is at least 754 hours

Given that the random sample size 'n' =29

Given that the mean life of sample x⁻ = 737

Given that the standard deviation of the Population = 59

Step(ii):-

Null hypothesis: H₀: μ≥ 754

Alternative Hypothesis:H₁: μ≤ 754

Test statistic

           [tex]Z = \frac{x^{-}-mean }{\frac{S.D}{\sqrt{n} } }[/tex]

           [tex]Z = \frac{737-754 }{\frac{59}{\sqrt{29} } }[/tex]

           Z =  -1.55

The calculated test  |Z| = |-1.55| >1.405 at 0.08 level of significance

The null hypothesis is rejected  at 0.08 level of significance

Final answer:-

The calculated test  |Z| = |-1.55| >1.405 at 0.08 level of significance

The null hypothesis is rejected at a 0.08 level of significance.

A light bulb manufacturer guarantees that the mean life of a certain type of light bulb is at most 754 hour

Answer:

im pretty sure its 1.63

Step-by-step explanation:

lmk if im wrong

Answer:

New coordinates of the point Z are (-6, 9)

Step-by-step explanation:

If a point (x, y) is rotated 180° about the origin, coordinates of the image point is given by the rule,

(x, y) → (-x, -y)

Coordinates of the vertex Z → (6, -9)

Following the same rule,

Z(6, -9) → Z'(-6, 9)

Therefore, coordinates of the new (image) point will be (-6, 9).

Answer:

-2 -4 -6 -8

Step-by-step explanation:

I got the answer off of khan academy

Answer: n = 4

Step-by-step explanation:

Divide both sides by 3

n+2=3(6−n)

Expand

n+2=18−3n

Subtract 2 from both sides

n=18−3n−2

Simplify 18−3n−2 to −3n+16.

n=−3n+16

Add 3n to both sides

n+3n=16

Simplify n+3n to 4n

4n=16

Divide both sides by 4

n= 4/16

​

Simplify 16/4 to4

n=4

Answer:

Di ko po alam sorry

Step-by-step explanation:

Di ko alam putaenamo

Answer:

The mean is 78

The Median is 80.5

And The Mode is 58.

Step-by-step explanation:

(Mean) 86,75,97,58,94, and 58 equal 468. Divide it by 6 (The Total Of All The Numbers) and it gives you 78.

(Mode) Find the number that occurs the most which would be 58.

(Median) Put the numbers in order. Order: 58,58,75,86,94,97. Next, your supposed to find the number in the middle, but since there are 2(75 and 86.)

Add them together and you get 161. After that, divide them by 2 and it'll give you 80.5

By the way, if the number of numbers in the problem add up to be an even number, divide it by 2 and find the average. If it's odd, divide it by 2 and round it up to get to the median.

So yes, the teacher should use the scores to convince Maria that she needs to study more regularly for her exams.

The mean, median, or mode of the exam scores is 78, 86 and 58

The mean (average) of a data set is found by adding all numbers in the data set and then dividing by the number of values in the set.

The median is the middle value when a data set is ordered from least to greatest.

The mode is the number that occurs most often in a data set.

Given data: 58, 58, 75, 86, 94, 97

1. Mean= sum of observation/ Total number observation

= 58+58+75+86+94+97/6

=468/6

=78

2. Median,

Since, n is even

median= (n/2)+ 1

= 6/2 + 1

= 3+1

=4 th term= 86

3. Mode: Mode is the repeating data

mode= 58

Learn more about mean , median and mode here:

https://brainly.com/question/15323584

#SPJ2

Answer:

B          (-2x - 3 )(x - 7) =  (x - 7)(-2x - 3 )

Step-by-step explanation:

y = -2x² + 11x + 21

find x when y is zero  (the ground)

(-2x - 3 )(x - 7) = 0

(-2x - 3 )  = 0,   (x - 7) = 0

  x = -1.5   and   x = 7   since Jon did not throw the ball behind him (remember he is standing on a platform)  the only possible answer is 7 feet in front of him, but they the question didn't ask for x, so I would answer B.  The answer I got and multiplicans are in reverse order from their choice.

The  factored form of the expression that could be used to find out how far the ball has traveled horizontally when it hits the ground is (x-7)(-2x-3)

A quadratic equation is a second-order polynomial equation in a single variable x , ax² +bx+c=0. with a ≠ 0 .

Given that Jon throws a ball into the air off a platform.

The height of the ball is given by y equal minus 2 x to the power of 2 plus 11 x plus 21

y= -2x² + 11x + 21.

Let us factor out the equation by quadratic equation

-2x² + 11x + 21

When we factor out the equation becomes as (x-7)(-2x-3)

Let us verify the solution by applying distribution property

-2x²-3x+14x+21

-2x²+11x+21

Hence, (x-7)(-2x-3) is the  factored form of the expression that could be used to find out how far the ball has traveled horizontally when it hits the ground.

To learn more on Quadratic equation click:

https://brainly.com/question/17177510

#SPJ3

Answer:

It's 18

Step-by-step explanation:

30/100 x 60/1

180/100 =18

Answer:

18

Step-by-step explanation:

Here. We are going to multiply both sides of the equation by this fraction 100 over 30 100 over 30.

Answer: D!! also 35% are spotted

Answer:

The answer is a.

Step-by-step explanation:

This is because the percent is out of 100 and the flock of spotted sheep is placed in the numerator.

Answer:

y=10

Step-by-step explanation: a horizontal line has no slope

Answer: $5175.75

Step-by-step explanation:

The amount that is paid in total to buy the stock will be gotten through the addition of the cost of the shares and the commission paid. This will be:

= (200 × $25.75) + $25.75

= $5150 + $25.75

= $5175.75

Therefore, the total amount that is paid to buy the stock will be $5175.75.

Answer:

2×8=16

7×3=21

2/3 + 7/8 = 16/24 + 21/24

Answer:

ABCD in statement and the other in reasoning

Step-by-step explanation:

Answer:

40

Step-by-step explanation: pls I need points make brainpy

Answer:

2. dM/dt = -0.11M

Step-by-step explanation:

Differential equations for proportional amouts:

A differential equation for proportional amounts is given by:

[tex]\frac{dx}{dt} = ax[/tex]

In which a is the constant rate. If the amount increases, a is positive. If it decays, b is positive.

In this question:

Decays, so a < 0.

Proportional to the amount of the substance present at a given time, which means that a multiplies the amount M.

This means that the correct answer is given by option 2.

Answer:

4.2%

Step-by-step explanation:

The horizontal distance, x (Run) = 22 feets

Rise, vertical distance, y = 11 inches

The slope is the ratio of the vertical to the horizontal distance, Rise to Run

Slope = Rise / Run

Converting to the same unit ;

Foot to inches

1 foot = 12 inches

Hence, x = 22 feets = (12 * 22) = 264 inches

Slope = Rise / Run = 11 / 264 = 0.04167

Slope = 0.04167 * 100% = 4.167%

Answer:

The median of the following numbers is 14

Step-by-step explanation:

Answer:

n2

Step-by-step explanation:i did this last year

The Answer Is Y=-8x

This is because x is multiplied by -8 to find y.

Answer:

3

Step-by-step explanation:

I think

Answer:

less than or equal to 3

Step-by-step explanation:

Answer:

30 cubic inch

Step-by-step explanation:

Answer:

x + (3-2) = 12

Step-by-step explanation:

x + (3-2) = 12

or x + 1 = 12

so x = 11

Answer:

b. It is a symmetric distribution, as the mean and the median are the same.

Step-by-step explanation:

Normal distribution:

The biggest characteristic of the normal distribution is that it's symmetric, that is, 50% of the values are below the mean and 50% are above, which means that the mean is the same as the median.

This means that the correct answer is given by option b.

Answer:

30,000 + 2,000 + 400 + 50 + 6

Step-by-step explanation:

[tex]\text{The expanded form of 32,456 would be 30,000 + 2,000 + 4,000 + 50 + 6.}[/tex]

[tex]\text{We would have to identify what each number stands for.}[/tex]

[tex]\text{For example, 3 in 32,456 stands for 30,000.}[/tex]

[tex]\text{Hence, following this rule, we can conclude that the answer above is correct.}[/tex]

[tex]\text{I hope I helped you suceed!}[/tex]