A market research firm supplies manufacturers with estimates of the retail sales of their products from samples of retail stores. Marketing managers are prone to look at the estimate and ignore sampling error. A random sample of 36 stores this year shows mean sales of 53 units of a small appliance with a standard deviation of 12 units. During the same point in time last year, a random sample of 49 stores had mean sales of 41 units with standard deviation 6 units.

It is of interest to construct a 95 percent confidence interval for the difference in population means ?1??2, where ?1 is the mean of this year's sales and ?2 is the mean of last year's sales.

Enter values below rounded to three decimal places.

(a) The estimate is: _________ .

(b) The standard error is: ____________________ .

Answers

Answer 1

Answer:

The 95% confidence interval for the difference of means is (7.67, 16.33).

The estimate is Md = 12.

The standard error is sM_d = 2.176.

Step-by-step explanation:

We have to calculate a 95% confidence interval for the difference between means.

The sample 1 (this year's sales), of size n1=36 has a mean of 53 and a standard deviation of 12.

The sample 2 (last year's sales), of size n2=49 has a mean of 41 and a standard deviation of 6.

The difference between sample means is Md=12.

[tex]M_d=M_1-M_2=53-41=12[/tex]

The estimated standard error of the difference between means is computed using the formula:

[tex]s_{M_d}=\sqrt{\dfrac{\sigma_1^2}{n_1}+\dfrac{\sigma_2^2}{n_2}}=\sqrt{\dfrac{12^2}{36}+\dfrac{6^2}{49}}\\\\\\s_{M_d}=\sqrt{4+0.735}=\sqrt{4.735}=2.176[/tex]

The degrees of freedom are:

[tex]df=n_1+n_2-1=36+49-2=83[/tex]

The critical t-value for a 95% confidence interval and 83 degrees of fredom is t=1.989.

The margin of error (MOE) can be calculated as:

[tex]MOE=t \cdot s_{M_d}=1.989 \cdot 2.176=4.328[/tex]

Then, the lower and upper bounds of the confidence interval are:

[tex]LL=M_d-t \cdot s_{M_d} = 12-4.328=7.67\\\\UL=M_d+t \cdot s_{M_d} = 12+4.328=16.33[/tex]

The 95% confidence interval for the difference of means is (7.67, 16.33).


Related Questions

Mr. Hobbs took out a loan of $12,000 for 4 years at a simple annual
interest rate of 7%. How much interest did he pay?

Answers

Answer:

Step-by-step explanation:

I= P*r*t

I = 12000* 7% *4

Total interest paid was $3360.

Answer: $3,360

Step-by-step explanation:

Select and place the symbol that will make the statement true |-a| |a|

Answers

Answer:

|-a|=|a|

Step-by-step explanation:

The lines beside the a's mean that you are trying to find the absolute value of what's inside. The absolute value of something is the distance it is from 0. You can't have a negative distance so anything inside of absolute value line are positive.

Therefor this is how we can solve this.

|-a| __ |a|

  a __ a

a=a

Design and complete a frequency table for Belinda.
Belinda ask 20 people, how many hours of TV did you watch last week?

Here is the results
3,17,4,4,6,11,14,14,1,20,9,8,9,6,12,7,8,13,13,9.
Belinda wants to show these result in a frequency table.
She will use 4 equal groups.
The first group will start with 1 hour and the last group will end with 20 hours.

Answers

Answer:

Step-by-step explanation:

Since she will use 4 groups or class intervals, the the class width would be 20/4 = 5 hours

The class groups would be

1 to 5

5 to 10

10 to 15

15 to 20

The class mark for each class is the average of the minimum and maximum value of each class. Therefore, the class marks are

(1 + 5)/2 = 3

(5 + 10)/2 = 7.5

(10 + 15)/2 = 12.5

(15 + 20)/2 = 17.5

The frequency table would be

Class group Frequency

1 - 5 4

5 - 10 8

10 - 15 6

15 - 20 2

The total frequency is 4 + 8 + 6 + 2 = 20

A tree grows three feet per year. What happens to the growth of the
When the number of years increases, the number of feet decrea
When the number of years decreases, the number of feet stays
When the number of years increases, the number of feet increas
When the number of years decreases, the number of feet increa

Answers

Answer:

The answer is C :,)

Step-by-step explanation:

Answer:

The answer to your question is c

Step-by-step explanation:

Because the years have to increase for it to grow.

Could someone please help me with the steps for this problem? Factor by grouping: w²+3w+w+3

Answers

Answer:

Please see steps below

Step-by-step explanation:

In order to factor by grouping, we divide the four terms given into two groups, and extract on each group any common factor  we can.

In our example, we can select the terms: [tex]w^2[/tex]  and [tex]w[/tex] as one of our groups, and [tex]3w[/tex] and 3 in the other group. Then we re-organize the expression as:

[tex](w^2+w)+(3x+3)[/tex]

Now we extract from the first binomial group, the factor [tex]w[/tex] as a common factor of both terms, and from the second group we extract the factor "3" as common factor of those two terms:

[tex](w^2+w)+(3x+3)\\w(w+1)+3(w+1)[/tex]

We notice now that after the extraction, we are left with two exactly equal binomial factors [tex](w+1)[/tex] that appeared in the first group and in the second group. We proceed then to extract it as common factor for the two groups:

[tex]w(w+1)+3(w+1)\\(w+1)(w+3)[/tex]

this last product of two binomials ([tex](w+1)\,(w+3)[/tex] is the result of factoring the original expression.

What’s the correct answer for this question?

Answers

Answer:

Height = 12 inches

Step-by-step explanation:

Volume = Area × Height

1080 = 90 × H

H = 1080/90

H = 12 inches

85 points!! | All of the following expressions have the same value, when x= -2 and y= 4, except
-2xy
0-4x2
0x²y
0 (-2) ²y

Answers

Answer:

They have two sets of equal answers...

Step-by-step explanation:

-2 * 2 * 4 = -16

0 - 4 * -2 * -2 = -16

0 * -2 * -2 * 4 = 0

0 * 4 * 4 = 0

Find lim x→3 sqrt 2x+3-sqrt 3x/ x^2-3x. you must show your work or explain your work in words plsss I need help

Answers

I'm assuming the limit is supposed to be

[tex]\displaystyle\lim_{x\to3}\frac{\sqrt{2x+3}-\sqrt{3x}}{x^2-3x}[/tex]

Multiply the numerator by its conjugate, and do the same with the denominator:

[tex]\left(\sqrt{2x+3}-\sqrt{3x}\right)\left(\sqrt{2x+3}+\sqrt{3x}\right)=\left(\sqrt{2x+3}\right)^2-\left(\sqrt{3x}\right)^2=-(x-3)[/tex]

so that in the limit, we have

[tex]\displaystyle\lim_{x\to3}\frac{-(x-3)}{(x^2-3x)\left(\sqrt{2x+3}+\sqrt{3x}\right)}[/tex]

Factorize the first term in the denominator as

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

The [tex]x-3[/tex] terms cancel, leaving you with

[tex]\displaystyle\lim_{x\to3}\frac{-1}{x\left(\sqrt{2x+3}+\sqrt{3x}\right)}[/tex]

and the limand is continuous at [tex]x=3[/tex], so we can substitute it to find the limit has a value of -1/18.

What’s the correct answer for this question?

Answers

Answer:

the radius

Step-by-step explanation:

the correct answer is the radius

Answer the inequality

Answers

Answer:

A.

Step-by-step explanation:

Add 4:

-5x ≤ 10

Divide by -5:

x ≥ -2

A car travelled 80km in 48minutes. find the speed of the car in km/hr​

Answers

80km / 48 min = 1 2/3 km per minute.

1 2/3 km per minute x 60 minutes(1 hour) = 100 km per hour

ASAP! GIVING BRAINLIEST! Please read the question THEN answer CORRECTLY! NO guessing. I say no guessing because people usually guess on my questions.

Answers

Answer:

The correct answer would be A

(I am not guessing I had the same quiz before)

What is the answerrrrrrrrrrrr :(((((((((((

Answers

Answer: The answer is choice 3

Step-by-step explanation:

i think the answer is c

Step-by-step explanation:

i don't think u would want a whole explanation

How many tons is 22,000 pounds?

Answers

Answer:

1 ton = 2,000 pounds

Step-by-step explanation:

With that said, 22,000 pounds is 11 tons because 2,000 x 11 = 22,000.

So 22,000 pounds is 11 tons.

Hope it helps and pls mark me brainliest if it did! :)

Is 3/5 A.irrational, B.rational, C.natural and whole, or D.natural, whole integer and rational

Answers

Answer:

B

Step-by-step explanation:

3/5 is a fraction, meaning it isn't irrational, natural, whole or an integer, therefore the answer is rational (B).

Answer:

B.rational

Step-by-step explanation:

3/5 is written as a fraction so it is a rational number

It is not a whole number since it is a reduced fraction that is less than 1

Complete the statements with equal to, greater than, or less than. 5 6 × 6 9 is ? 5 6 . 6 × 5 6 is ? 5 6 . 5 6 × 9 9 is ? 5 6 . 5 6 × 8 7 is ? 5 6 . 7 7 × 5 6 is ? 5 6 . 5 6 × 5 6 is ? 5 6 .

Answers

Answer:

someone already answered

Step-by-step explanation:

srry

HELP PLEASE SIMPLIFY !!!

Answers

Answer:

[tex]=x^{\frac{5}{6}}+2x^{\frac{7}{3}}[/tex]

Step-by-step explanation:

[tex]x^{\frac{1}{3}}\left(x^{\frac{1}{2}}+2x^2\right)\\\mathrm{Apply\:the\:distributive\:law}:\quad \:a\left(b+c\right)=ab+ac\\a=x^{\frac{1}{3}},\:b=x^{\frac{1}{2}},\:c=2x^2\\=x^{\frac{1}{3}}x^{\frac{1}{2}}+x^{\frac{1}{3}}\cdot \:2x^2\\=x^{\frac{1}{3}}x^{\frac{1}{2}}+2x^2x^{\frac{1}{3}}\\\mathrm{Simplify}\:x^{\frac{1}{3}}x^{\frac{1}{2}}+2x^2x^{\frac{1}{3}}:\quad x^{\frac{5}{6}}+2x^{\frac{7}{3}}\\x^{\frac{1}{3}}x^{\frac{1}{2}}+2x^2x^{\frac{1}{3}}\\x^{\frac{1}{3}}x^{\frac{1}{2}}=x^{\frac{5}{6}}[/tex]

[tex]x^{\frac{1}{3}}x^{\frac{1}{2}}\\\mathrm{Apply\:exponent\:rule}:\quad \:a^b\cdot \:a^c=a^{b+c}\\x^{\frac{1}{3}}x^{\frac{1}{2}}=\:x^{\frac{1}{3}+\frac{1}{2}}\\=x^{\frac{1}{3}+\frac{1}{2}}\\\mathrm{Join}\:\frac{1}{3}+\frac{1}{2}:\quad \frac{5}{6}\\\frac{1}{3}+\frac{1}{2}\\\mathrm{Least\:Common\:Multiplier\:of\:}3,\:2:\quad 6\\Adjust\:Fractions\:based\:on\:the\:LCM\\=\frac{2}{6}+\frac{3}{6}[/tex]

[tex]\mathrm{Since\:the\:denominators\:are\:equal,\:combine\:the\:fractions}:\quad \frac{a}{c}\pm \frac{b}{c}=\frac{a\pm \:b}{c}\\=\frac{2+3}{6}\\\mathrm{Add\:the\:numbers:}\:2+3=5\\=\frac{5}{6}\\=x^{\frac{5}{6}}\\2x^2x^{\frac{1}{3}}=2x^{\frac{7}{3}}\\=x^{\frac{5}{6}}+2x^{\frac{7}{3}}[/tex]

The value of m compared to the standard is
1/1000
1000
1/100
10

Answers

Idk either but it looks like the reciprocal so I would guess 1/m

One third of the sum of 15
and thrice a certain number is
equal to twice the number. Find
the number​

Answers

Answer:

x=-1/39

Step-by-step explanation:

In a survey, participants were asked how much confidence they had in the economy.
The results were as follows:



Response Number

A great 3,187
deal

Some
9,120

Hardly 5,149
any



What is the probability that a sampled person has either some confidence or a great
deal of confidence in the economy? Write only a number as your answer. Round to
two decimal places (for example: 0.43). Do not write as a percentage.

Answers

Answer:

0.71

Step-by-step explanation:

Great Deal or Some = 12,307

Total Participants = 17,456

Probability = 12,307/17,456 = 0.71

B point is (-5,-4) moves through the translation (x+1 , y-3) what will be the coordinates of B

Answers

Answer:

(-4,-7)

Step-by-step explanation:

Adding 1 to the x and subtracting 3 from the y we get

-5+1= -4

And

-4-3= -7

The top of a lighthouse is 100 m above sea level. The angle of elevation from the
deck of the sailboat to the top of the lighthouse is 28°. Calculate the distance
between the sailboat and the lighthouse.

Answers

Answer:

  188 m

Step-by-step explanation:

The tangent of the angle is the ratio of the side opposite (height of the lighthouse) to the side adjacent (distance to the lighthouse):

  tan(28°) = (100 m)/distance

  distance = (100 m)/tan(28°) ≈ 188 m

The distance between the sailboat and the lighthouse is about 188 m.

ACB = DCE
A = 3x-10, C = 45°, D = 2x+10
Please help confused

Answers

Answer:

  x = 20

Step-by-step explanation:

The congruence statement tells you that angle A is congruent to angle D. (Both are listed first in the triangle names.) This means ...

  ∠A = ∠D

  3x -10 = 2x +10

  x = 20 . . . . . . . . . . add 10-2x to both sides

Use Newton's method with initial approximation x1 = 1 to find x2, the second approximation to the root of the equation x4 − x − 3 = 0. (Round your answer to four decimal places.) x2 =?

Answers

Answer:

[tex]x_{2} = 0.0000[/tex]

Step-by-step explanation:

The formula for the Newton's method is:

[tex]x_{i+1} = x_{i} + \frac{f(x_{i})}{f'(x_{i})}[/tex]

Where [tex]f' (x_{i})[/tex] is the first derivative of the function evaluated in [tex]x_{i}[/tex].

[tex]x_{i+1} = x_{i} + \frac{x_{i}^{4}-x_{i}-3}{4\cdot x_{i}^{3}-1}[/tex]

Lastly, the value of [tex]x_{2}[/tex] is determined by replacing [tex]x_{1}[/tex] with its numerical value:

[tex]x_{2} = x_{1} + \frac{x_{1}^{4}-x_{1}-3}{4\cdot x_{1}^{3}-1}[/tex]

[tex]x_{2} = 1.0000 + \frac{1.0000^{4}-1.0000-3}{4\cdot (1.0000)^{3}-1}[/tex]

[tex]x_{2} = 0.0000[/tex]

solve 5(x+4)<75 sdsdsd

Answers

Answer:

x < 11

Step-by-step explanation:

[tex]5(x+4)<75 \\ open \: the \: bracket \: using \: 5 \\ 5x + 20 < 75 \\ subtract \: - 20 \: from \: both \: sides \: [/tex]

[tex]5x + 20 - 20 < 75 - 20 \\ 5x < 55 \\ divide \: both \: sides \: of \: the \: equation \: \\ by \: 5[/tex]

[tex] \frac{5x}{5} < \frac{55}{5} \\ x < 11[/tex]

The required solution of inequality is,

⇒ x < 11

We have to simplify the expression,

⇒ 5 (x + 4) < 75

We can simplify it by definition of inequality as,

⇒ 5 (x + 4) < 75

⇒ 5x + 20 < 75

Subtract 20 both side,

⇒ 5x + 20 - 20 < 75 - 20

⇒ 5x < 55

⇒ 5x - 55 < 0

⇒ 5 (x - 11) < 0

⇒ x - 11 < 0

⇒ x < 11

Therefore, The required solution of inequality is,

⇒ x < 11

Learn more about the inequality visit:

https://brainly.com/question/25944814

#SPJ6

Every product manufactured by a company goes through 6 different tests before being shipped out. It is known that the probability that a product passes any single test is 0.9 and the tests are independent. Only those products that pass the first three tests and also pass at least one of the three remaining tests are shipped out. Find the probability that a manufactured product is shipped out.

Answers

Answer:

The Probability that the product is shipped out is 0.7283

Step-by-step explanation:

Here, we are given that, a product passes through 6 tests before it is shipped out and a product is shipped out only if it passes all the first 3 tests and at least 1 of the remaining 3 tests.

We have P(pass)= 0.9, is the Probability of passing any test.

Which implies, P(fail)= 1- 0.9= 0.1

We have to find the Probability that the product is shipped out.

P(product is shipped out) = P(it passes first 3 tests )*P(passes at least 1 of the remaining 3 tests) •••••••••••(i)

We can take the product as the tests are Independent.

Now, let us obtain

P(it passes first 3 tests ) = P(pass)*P(pass)*P(pass)

=P(pass)]^3 = (0.9)^3 = 0.729

Hence, P( it passes first 3 tests)= 0.729 •••••••(ii)

Now,

P(passes at least 1 of the remaining 3 tests)

= 1-P(fails all the 3 remaining tests)

= 1-(0.1)^3 = 1 - 0.001 = 0.999

Hence,

P(passes atleast 1 of the remaining 3 tests)=0.999 ••••••••(iii)

Now, substituting the 2nd and 3rd equations in the first equation, we have;

P(product is shipped out) = P(it passes first 3 tests )*P(passes at least 1 of the remaining 3 tests)

= (0.729)*(0.999)

= 0.728271

= 0.7283

Please answer this correctly without making mistakes

Answers

Answer:

589

Step-by-step explanation:

l x w

19x11

5x31

5x45

589

Answer:

589 is the answer

Consider a manufacturing process with a quality inspection station. In the past, 10% of parts are defective. As soon as one defective part is found, the process is stopped. If 6 parts have been inspected without finding a defective part, what is the probability that at least 9 total parts will be inspected before the process is stopped

Answers

Answer:

0.9

Step-by-step explanation:

10% is equal to 0.1

The probability of having defective parts in a pile of parts is 0.1

Before the process is stopped, 1 part has to be defective.

In a pile of 9 parts, the probability that a part is defective 0.1 of 9, which is = 0.9 hence, approximately one (1) part will be defective in a pile of 9 parts and the process will be stopped.

Since there was no defective part among the first 6 parts, P(d) was 0

That is, probability of a defective part was zero.

Triangles E F G and K L M are shown. Angles E F G and K L M are congruent. The length of side K L is 6, the length of side M L is 5, and the length of K M is 8. The length of E G is 24, the length of G F is 15, and the length of E F is 18. Can the triangles be proven similar using the SSS or SAS similarity theorems? Yes, △EFG ~ △KLM only by SSS. Yes, △EFG ~ △KLM only by SAS. Yes, △EFG ~ △KLM by SSS or SAS. No, they cannot be proven similar by SSS or SAS.?

Answers

Answer:

The Answer is C: Yes, △EFG~ △KLM by SSS or SAS

Step-by-step explanation:

SSS is for side-side-side

Both triangles have all three sides given, so the SSS similarity theorem is one way to prove these triangles are similar.

SAS is for side-angle-side

Both triangles have one angle measurement given, and two side lengths given, therefore we can also use the SAS similarity theorem to prove the two triangles are similar.  

Since both SSS and SAS work to prove the triangles are similar, the correct answer is C: Yes, △EFG~ △KLM by SSS or SAS

(I also just answered this question on the assignment and got it correct)

Answer:

Answer is C

Step-by-step explanation:

Took it on Edg

Calculating a correlation can help describe a relation between two quantitative variables' ___ and ___ . However, it is not sufficient to use a correlation coefficient to describe two variables. The addition of ___ can provide other helpful details such as __ _."

Answers

Answer:

direction

shape

scatter plots

shape and outliers

Step-by-step explanation:

Correlation is defined as the degree of correspondence between two variables.

When the values increase together, correlation is positive and when one value decreases as the other increases, correlation is negative .

Calculating a correlation can help describe a relation between two quantitative variables' direction and shape. However, it is not sufficient to use a correlation coefficient to describe two variables.  The addition of scatter plots can provide other helpful details such as shape and outliers

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