A manufacturer claims that the mean lifetime,u , of its light bulbs is 51 months. The standard deviation of these lifetimes is 7 months. Sixty bulbs are selected at random, and their mean lifetime is found to be 53 months. Can we conclude, at the 0.1 level of significance, that the mean lifetime of light bulbs made by this manufacturer differs from 51 months?
Perform a two-tailed test. Then fill in the table below.
Carry your intermediate computations to at least three decimal places, and round your responses as specified in the table. (If necessary, consult a list of formulas.)
the null hypothesis:
The alternative hypotehsis:
The type of test statistic (choose Z, t, Chi-square, or F)
The value of the test statistic (round to at least three decimal places:
Can we conclude that the mean lifetime of the bulbs made by this manufacture differ from 51 months?

Answers

Answer 1

Answer:

We reject  H₀, and conclude thet the mean lifetime of the bulbs differ from 51 month

Step-by-step explanation:

Manufacturing process under control must produce items that follow a normal distribution.

Manufacturer information:

μ  =  51 months     mean lifetime

σ  =  7 months       standard deviation

Sample Information:

x  =  51 months

n  =  60

Confidence Interval  =  90 %

Then significance level  α  =  10 %  α  =  0.1    α/2  =  0,05

Since it is a manufacturing process the distribution is a normal distribution, and with   n = 60 we should use a Z test on two tails.

Then from z- table z(c) for  α = 0,05  is  z(c)  = 1.64

Hypothesis  Test:

Null Hypothesis                              H₀            x  =  μ

Alternative Hypothesis                  Hₐ            x ≠  μ

To calculate z statistics  z(s)

z(s)  =   (  x   -  μ )  / σ /√n

z(s)  =   (  53  -  51 ) / 7 /√60

z(s)  =  2 * 7.746 / 7

z(s)  = 2.213

Comparing  z(s)  and  z(c)

z(s)  >  z(c)   then  z(s)  is in the rejection region

We reject  H₀, and conclude thet the mean lifetime of the bulbs differ from 51 month


Related Questions

Factor of 15x - 20y

Answers

Answer:

0

Step-by-step explanation: Solving for variable 'x'.

Move all terms containing x to the left, all other terms to the right.

Add '-20y' to each side of the equation.

15x + 20y + -20y = 0 + -20y

Combine like terms: 20y + -20y = 0

15x + 0 = 0 + -20y

15x = 0 + -20y

Remove the zero:

15x = -20y

Divide each side by '15'.

x = -1.333333333y

Simplifying

x = -1.333333333y

4. Type of data that is given as individual data points.
a grouped
c. research
b. questionnaire
d. un grouped​

Answers

Answer:

Ungrouped

Step-by-step explanation:

Data given as individual data points are usually called Ungrouped data, this is because the data given is raw and not arranged in intervals to form a group of data. This data are usually worked on without having to work with the class size or the midpoint of the intervals. Examples of Ungrouped data could be given as a list of values such as :

Ages of 10 randomly chosen children :

5, 4, 2, 2, 4, 5, 7, 6, 3, 4

which expression has a value of 15 when n=7?​

Answers

8+n is a possible answer to the question.

Answer:

19 - 28/n

n=7

19 - 28/7

19 - 4

=15

Show Intro/Instructions
A wire 15 centimeters long is cut into two pieces. The longer piece is 3 centimeters longer than
the shorter piece. Find the length of the shorter piece of wire.

Answers

Answer:

Let the length of the 2 pieces = L and S

Let L = the longer piece and S = the shorter piece

A wire 26 cm is cut into 2 pieces.  This equates to......L + S = 26

The longer piece is 6 cm longer than the shorter piece.  This equates to.....L = 6 + S.  Substitute this equation into the first one, you get

L + S = 26

6 + S + S = 26

2S = 20

S = 20/2 = 10 cm

L = 6 + S = 6 + 10 = 16 cm

To confirm, L + S = 26

16 + 10 = 26!

Hope the above was helpful.

Step-by-step explanation:

A.)55
B.)38
C.)70
D.)20

Answers

Answer:

D) 20

Step-by-step explanation:

4x - 10  and x together equal 90

Set your formula up as

90 = 4x - 10 + x

90 + 10 = 4x + x

100 = 5x

100 / 5 = x

20 = x

Which mathematical sentence most Accurately expresses the information in the problem below?

See Picture....

Answers

Answer:

Don't quote me on this but it's probably C. 12c ≥ 88

Step-by-step explanation:

This is because he packages 88 eggs into cartons of 12.

88/12 is 7.33333... so it makes sense to have a greater or equal amount of eggs. If you multiply 7.333333... by 12, each additional 3 gets you closer to 88 so again, makes sense to have more.

Smedley has two rolls of crepe paper, one with 30 yards and one with 40 yards. If he cuts both rolls into 5-yard streamers, how many streamers will he have?​

Answers

Answer:

He will have 14 streamers

Answer:

2

Step-by-step explanation:

so u multiply it by 2846 take away the 8, 4 and 6 and all ur left is with 2

solve 14a-3b+9c=18 for a. Do not use a= in your answer

Answers

Answer:

9/7 + 3/14b  - 9/14c

Step-by-step explanation:

See image below:)

This makes no sense, help pls

Answers

Please mark me branliest!

**Answer**

16 if you want exact, 20 if you want a little over.

**Explanation**

So check this... it's $50 per student that attends the camp, right?

(Nod if you're with me.)

The dude buys 5 dozen donuts for 16 days. 50 x 16 = 800

5 dozen is the same as 50 donuts.

You multiply to get the total amount of donuts he buys in the total days (16).

Each 10 donuts costs 10 dollars.

If the dude buys 800 donuts it cost him $800.

And it costs 50 dollars for someone to go to camp.

So you divide 800/50 = 16 students

Now the problem says "In order to break even" I'm not sure what that means. But I'm assuming it doesn't want 16 then, because the price of 16 students would be the same (even) as the price of donuts that Mr. Brook buys. In that case it would be 20.

You are very welcome!!

In 2015, Tamya spent 100 hours reading. In 2016, she has only read 9.5 hours. How many more hours does she have to read in order to also read 100 hours in 2016?​

Answers

Answer:

90.5 hours or 90 hours and 30 minutes

Step-by-step explanation:

100-9.5=90.5

Which type of triangle is it possible for an obtuse triangle to be?
acute triangle
equilateral triangle
isosceles triangle
right triangle

Answers

isosceles triangle should be right because i has the exact same question


Find the area of each sector. Round your answers to the nearest tenth.

Answers

Answer:

a = 117.3 cm²

Step-by-step explanation:

a = (1/2)∅r²

a = (1/2)(7π/6)(8²)

a = (1/2)(7 * 3.14159/6)(64)

a = 117.3 cm²

Mention any two similarities between rectangle and square.​

Answers

Squares and rectangles both are a type of quadrilateral, both have their four interior angles equal to 90 degrees and opposite sides parallel to each other.

The similarities between a rectangle and a square as:

All 4 angles are 90 deg each.

Opposite sides are parallel and equal.

The diagonals bisect each other.

Circles can circumscribe both figures.

The diagonals form the diameter of the circumscribing circle.

The square root of the sum of the squares of adjacent sides is the diagonal.

The area is the product of adjacent sides.

The diagonals bisect the figure into 2 congruent triangles.

Join the midpoints of opposite sides and you get 4 similar figures of 1/4 the area of the original figure.

Join the midpoints of 4 sides in order and you get a rhombus, whose area is half that of the original figure.

what additional piece of information do we need to prove that MLN ≅ OPN

Answers

Answer:

N is the midpoint of MO

Step-by-step explanation:

Given

See attachment for triangles

Required

Additional information to prove [tex]MLN \cong OPN[/tex]

From the attachment, we already have:

[tex]LM \simeq OP[/tex] and [tex]LN \simeq ON[/tex]

The additional information that must be true for [tex]MLN \cong OPN[/tex]  to be true is: N is the midpoint of MO

Because this piece of information proves that:

[tex]MN \simeq ON[/tex]

Which in other words makes [tex]MLN \cong OPN[/tex]

Pls help LOL I WILL MARK U BRAINLIEST‼️‼️‼️‼️

Answers

Answer:

B=17

A=16

Step-by-step explanation:

It is my friend OK if you want say again and I can ans

Please HELP!
Given this graph of function f(x), find f (-2)

Answers

Answer:

4

Step-by-step explanation:

f(x) is just the y value for a given value of x

When x = -2     y = 4

f(-2) = 4

Please help, I’m so lost in math

Answers

Answer:

[tex]r = 15 \times 5 \\ r = 75[/tex]

Answer:

75

Step-by-step explanation:

5 = r/15

what we want to do is solve for r

to do this we want to isolate the variable (r) using inverse operations

5 = r / 15

so to solve for r we want to get rid of the 15

r is being divided by 15

the inverse of division is multiplication

so to get rid of the 15 we multiply by 15

but remember whatever we do to one side we must do to the other side, so we multiply each side by 15

15 * 5 = 75

r / 15 * 15 = r

we're left with r = 75

we can then check are work by substituting 75 for r and then see if the equation is true

5 = r/15

* substitute 75 for r *

5 = 75/15

75 / 15 = 5

we're left with 5 = 5 which is true

The function of f(x) = 3x + 2 has a domain of -3 < x < 5. What is the domain of f-1(x)?

Answers

Answer:    -7 < x < 17

====================================================

Explanation:

Plug in the lower bound of the domain, which is x = -3

f(x) = 3x+2

f(-3) = 3(-3)+2

f(-3) = -9+2

f(-3) = -7

If x = -3, then the output is y = -7. Since f(x) is an increasing function (due to the positive slope), we know that y = -7 is the lower bound of the range.

If you plugged in x = 5, you should find that f(5) = 17 making this the upper bound of the range.

The range of f(x) is -7 < y < 17

Recall that the domain and range swap places when going from the original function f(x) to the inverse [tex]f^{-1}(x)[/tex]

This swap happens because how x and y change places when determining the inverse itself. In other words, you go from y = 3x+2 to x = 3y+2. Solving for y gets us y = (x-2)/3 which is the inverse.

-----------------------

In short, we found the range of f(x) is -7 < y < 17.

That means the domain of the inverse is -7 < x < 17 since the domain and range swap roles when going from original to inverse.

The domain of the resulting function exists on all real values that is the domain is -∞ < f-1(x) < ∞

How to find the domain of an inverse function?

The domain of a function are the independent values of the function for Which it exists.

Given the function f(x) = 3x + 2

Find its inverse

y = 3x + 2

Replace x with y

x = 3y + 2

Make y the subject of the formula:

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

The domain of the resulting function exists on all real values that is the domain is -∞ < f-1(x) < ∞
Learn more on domain here: https://brainly.com/question/26098895

A community shares a vegetable garden in a park each summer. Last year, it took Sapphire 88 hours to plant the garden by herself. The year before, it took Varsha 66 hours to plant the same garden by herself.

This year, if Sapphire and Varsha work together to plant the same vegetable garden, it would take ??? hours.

What is ???

Answers

Answer:

37.71 hours

Step-by-step explanation:

Saphire

1garden/88hours

Varsha

1garden/ 66 hours

Together

1/88 + 1/66 = x

use 264 as common denominator

3/264 + 4/264 = 7/264

Together they can do 7 gardens in 264 hours

264/7 = 37.71 hours for 1 garden

-----------------------------------

Sometimes Brainly double types numbers

If you meant 6 hours and 8 hours

1/6 + 1/8 = x

4/24 + 3/24 = 7/24

24/7 = 3.43 hours

Which of the following is an example of quantitative data?
A person's Zip Code

The color of your car

A Person's Height

A person's city of residence

Answers

Answer:

a person's height

Step-by-step explanation:

thing that you can count

Answer:

a person's height helpful answer

What is the domain of the relation given by the set of ordered pairs shown?

{ ( - 3, 2 ), ( - 1, 0 ), ( - 3, 5 ), ( 2, - 3 ) }

List the domain as a set, in increasing order.

Answers

Step-by-step explanation:

the domain = {-3, -1, 2}

_____

The domain, as a set in increasing order, will be {-3, -1, 2}.

What are domain and range?

The domain means all the possible values of x and the range means all the possible values of y.

The set of ordered pairs shown below.

{(-3, 2), (-1, 0), (-3, 5), (2, -3)}

Then the domain, as a set in increasing order, will be

⇒ {-3, -1, 2}

More about the domain and range link is given below.

https://brainly.com/question/12208715

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FACTOR b2 – 18b + 81

Answers

Answer:

(b-9)^2

Step-by-step explanation:

b^2-18b+81

=b^2-(9+9)b+81

=b^2-9b-9b+81

=b(b-9)-9(b-9)

=(b-9)(b-9)

=(b-9)^2

Hope this helps u!!

An orthocenter is the intersection of three.....?

Answers

Answer:

i don't get it

Step-by-step explanation:

Answer: An orthocenter is the intersection of three: Altitudes in a triangle.

Step-by-step explanation:

Altitude--

An altitude is a line segment that originates from a vertex and is perpendicular to the line segment opposite to that vertex.

Orthocenter--

An orthocenter of a triangle is a point where the three altitudes of a triangle meet or intersect.In  a right angled triangle the orthocenter is the vertex of the triangle where the right angle is formed.

If a card is randomly selected, what is the probability that the card is any one suit, e.g., a diamond, heart, spade, or club?

Answers

Answer:

the probablity of anything is

(Number of desired outcomes) / (Number of total outcomes)

Step-by-step explanation:

Answer:

I'd assume 1/4

Step-by-step explanation:

there are only 4 different suits to pick from

Which expression represents "5 times the sum of 4 and y?"
A) 5•4 + y
B ) 5(4 + y)
C ) 4+5•y
D ) 4(5 + y)

Answers

I think the answer should be B

Because 5 times for both 4 and y

What is the probability that a randomly chosen person from this group is a
sophomore and attended the jazz band concert?
Round your answer to two decimal places.
A. 0.56
B. 0.52
C. 0.26
D. 0.31

Answers

Answer:

0.26 or C

Step-by-step explanation:

Basically you would do the sophomores that attended the jazz band concert (35) and divide that by the total number of students. (137) - - 35 ➗ 137 = .2554744526 round that to .26 or 0.26

The probability that a randomly chosen person from this group exists a sophomore and attended the jazz band concert is 0.31.

What is probability?

Probability exists about calculating or estimating how possible or 'probable' something exists to occur.

Let A be the event that a person exists a sophomore.

B be the event that a person attended volleyball game.

A∩B denote the event that a person exists a sophomore and attend volleyball game.

P be the probability of an event.

We have to estimate the value of P(A∩B),

Given: A∩B = 42

P(A∩B) = 42/137 = 0.3065 approximately equal to 0.31

P(A∩B) = 0.31.

The probability that a randomly chosen person from this group exists a sophomore and attended the jazz band concert is 0.31.

Therefore, the correct answer is option D. 0.31.

To learn more about probability refer to:

https://brainly.com/question/12675996

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How would you complete the square on the left side of this equation? x^2-6x=15 A. Add 6 to both sides of the equation. B. Subtract 6 from both sides of the equation. C. Add 9 to both sides of the equation. D. Subtract 9 from both sides of the equation. Please select the best answer from the choices provided A B C D

Answers

Answer:

C. Add 9 to both sides of the equation.

Step-by-step explanation:

Given

[tex]x^2 - 6x = 15[/tex]

Required

Complete the squares

We have:

[tex]x^2 - 6x = 15[/tex]

---------------------------------------------

Take the coefficient of -6 i.e. -3

Square it (-3)^2 = 9

Add 9 to both sides

---------------------------------------------

Hence, C is correct

What theorem shows that △NTM ≅△SMT?

Answers

Answer:

Step-by-step explanation:

Side, side angle (SSA)  theorem shows that △NTM ≅△SMT.

What is congruency?

We know two similar planer figures are congruent when we have sides or angles or both that are the same as the corresponding sides or angles or both.

From the given figure ΔNTM and ΔSMT share a common side MT.

Now, line segment SQ is congruent to line segment NQ and similarly line segment MQ and NQ, and hence line segment SM and NT are congruent and the angle formed by ∠STM and ∠NMT are also measure the same. because of the similar intersections of te line segments.

Therefore ΔNTM and ΔSMT are congruent by side, side angle theorem.

learn more about congruency here :

https://brainly.com/question/7888063

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Sketch a graph that has the following characteristics. (8 points: 2 points for each characteristic)
a. Crosses the y-axis at (0, 4)
b. Increases in the interval –12 ≤ x ≤ –2
c. Constant in the interval –2 ≤ x ≤ 2
d. Decreases in the interval 2 ≤ x ≤ 12

Answers

87 Step-by-step explanation:

Ill answer when i get the result

To purchase $14.400 worth of machinery for his business, Greg made a down payment of $1400 and took out a business loan for the rest. After 2 years of
paying monthly payments of $576.18, he finally paid off the loan.

Answers

Answer:

below

Step-by-step explanation:

cost of the machinery = $14,400

he paid a deposit of $1400

then later paid $576.18 for two years

two years = 24 months

= $576.18 *24

=$13,828.32

total amount paid

= initial deposit + amount paid in two years

= $1,400 + $13,828.32

=$15,228.32

so he finally paid $15,228.32

interest = selling price - original cost

= $15,228.32 - $14,400

=$828.32

therefore interest = $828.32

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