Bob has a bulb factory that produces white light bulbs. He sold some bulbs to Peter claiming that on average the service life of his bulbs is at least 980 hours. To test this claim Peter gathered information on the 20 bulbs purchased. He found that the mean service life is 960 and knows that the variance of service life for the population is . Which of the following statements properly analyzes Bob’s claim? Assume that the distribution service life of bulbs is normal.
a. Using a t-test you conclude that both types of bulbs have different mean service life at the 5% level.
b. Using a t-test you conclude that both types of bulbs have the same mean service life at the 5% level.
c. Using a z-test you conclude that both types of bulbs have the same mean service life at the 5% level.
d. Using a t-test you conclude that both types of bulbs have the same mean service life at the 1% level.
e. Using a z-test you conclude that both types of bulbs have different mean service life at the 5% level.

Answers

Answer 1

Answer:

a. Using a t-test you conclude that both types of bulbs have different mean service life at the 5% level.

Step-by-step explanation:

The t test will be used as

1) the sample size is less than 30

2) the population standard deviation is knows and is s= √200= 14.142

Using the test statistic

t= x- u/ s/ √n

t= 960-980/ 14.142/ √20

t= -0.316

It is one tailed test as the claim is

H0: u ≥ 980 and the alternate hypothesis is Ha : u< 980

The  critical region for one tailed test with n-1 = 20-1 = 19 degrees of freedom  is t < 1.729 for ∝= 0.05

The  critical region for one tailed test with n-1 = 20-1 = 19 degrees of freedom  is t < 2.539 for ∝= 0.01

Since the calculated value of t= -0.136  falls in the critical region we conclude that the null hypothesis is false and the average life of the bulbs is less than 980. We accept the alternate hypothesis.

Only choice a is correct.


Related Questions

For the diagram shown, find the measures of angles 4,5, and 6.

Answers

Answer:

wheres the diagram???

Step-by-step explanation:

Which combination of shapes can be used to create the 3-D figure?

a 3D figure with bases that are congruent regular polygons with 8 sides that are connected by congruent polygons which have a length greater than their width

Two regular octagons and eight congruent rectangles
Two regular pentagons and five congruent squares
Two regular octagons and eight congruent squares
Two regular pentagons and five congruent rectangles

Answers

A 3-D figure is a shape that its three surfaces can be observed at the same time.  Therefore, required answer to the given question is: A. Two regular octagons and eight congruent rectangles.

When the length, width and height of a given shape can be observed at the same time, then its is said to be in a 3-D. However, polygons are shapes which has 3 or mores sides. Examples are: trigon, hexagon, octagon etc.

Thus, since the 3-D figure required in the question has two bases in the shape of regular octagon, which should have 8 sides connected by congruent polygons of length greater than their width.

This implies that the sides of the figure must be made up of eight congruent rectangles, because the 3-D figure has eight regular sides (which would be the width of the rectangles). Then, the height of the figure would be the length of the rectangles.

So, the correct option to the given question is A. Two regular octagons and eight congruent rectangles.

A sketch is attached to this answer for more clarifications.

For reference: https://brainly.com/question/12504553

Answer:

Two regular octagons and eight congruent rectangles

Step-by-step explanation:

Based on the picture in my test, I am positive the description and the picture are of the same thing.  In the picture, I can see eight congruent rectangles and two octagons.  I also got this right on my test.

picture of object:

In ΔFGH, g = 340 cm, f = 240 cm and ∠F=139°. Find all possible values of ∠G, to the nearest degree.

Answers

Answer:

No possible triangles

Step-by-step explanation:

Deltamath

What is the area of a triangle with vertices (1,0) (5,0) (3,4)

Answers

Answer:

The area of the triangle is of 8 units of area.

Step-by-step explanation:

Answer:

The area of the triangle is of 21 units of area.

Step-by-step explanation:

The area of a triangle with three vertices [tex](x_1,y_1),(x_2,y_2),(x_3,y_3)[/tex] is given by the determinant of the following matrix:

[tex]A = \pm 0.5 \left|\begin{array}{ccc}x_1&y_1&1\\x_2&y_2&1\\1_3&y_3&1\end{array}\right|[/tex]

In this question:

Vertices (1,0) (5,0) (3,4). So

[tex]A = \pm 0.5 \left|\begin{array}{ccc}1&0&1\\5&0&1\\3&4&1\end{array}\right|[/tex]

[tex]A = \pm 0.5(1*0*1+0*1*3+1*5*4-1*0*3-0*5*1-1*1*4)[/tex]

[tex]A = \pm 0.5*(20-4)[/tex]

[tex]A = \pm 0.5*16 = 8[/tex]

The area of the triangle is of 8 units of area.

What is the answer pls it’s for a grade

Answers

The answer
2
Explanation
The median is the middle number and if you take off one side from the left and one side from the right until you have your middle number

Can some one please help me find the solution of the question

Answers

Answer:

x=16°

Step-by-step explanation:

tanθ=opposite/adjacent

tan(<CAB)=BC/AB

<CAB=tan⁻¹(21/29)=35.9097308°

tanθ=opposite/adjacent

tan(<DAB)=BD/AB

<DAB=tan⁻¹((21/2)/29)=19.90374954°

<CAB=<DAB+x

x=<CAB-<DAB

=35.9097308-19.90374954

x=16.00598126°

1
When rolling two number cubes, what is the probability of rolling at least one 6?
А
12
36
С
6
36
B
11
36
D
1
36

Answers

Answer:

The answer is D.

ab" that goes through points (0,9)
Write an exponential function in the form y
and (5,2187)

Answers

9514 1404 393

Answer:

  y = 9(3^x)

Step-by-step explanation:

We assume you want a function in the form ...

  y = a(b^x)

that passes through points (0, 9) and (5, 2187).

Filling in the given point values, we have ...

  9 = a(b^0) = a

  2187 = a(b^5) = 9(b^5) . . . . using the above value of 'a'

Dividing the second equation by 9 and taking the 5th root, we find b.

  (2187/9) = b^5

  243^(1/5) = b = 3

The exponential function is ...

  y = 9(3^x)

What is the base and the volume?​

Answers

Question:

What is the base and the volume?​

Answer:

557

Step-by-step explanation:

(12 x 12) + (12 x 12) + (17 x 17) =557

Help plz need to pass

Answers

Answer:

The answer would be 792

Step-by-step explanation:

Lateral surface area for this objects formula is 2lh + 2lb because of its rectangular prism shape.

44ft is the answer cause 5ft 13ft aid negativebut then add the 22ft twice you get the same cause it dilated so it’s 44ft

An automobile manufacturer has developed a new compact automobile. A random sample of 64 of the new automobiles showed that the automobiles had a sample mean mileage of 28.75 miles per gallon and a sample standard deviation of 3.4 miles per gallon. a) Find the 95% confidence interval for the population mean mileage, and state your conclusion. b) Find the 98% confidence interval for the population mean mileage, and state your conclusion.

Answers

Answer:

The 95% confidence interval for the population mean mileage is

(27.917, 29.593)

The 98% confidence interval for the population mean mileage

(27.737, 29.762)

Step-by-step explanation:

Step(i):-

Given that the random sample size 'n' = 64

Given that the mean of sample x⁻ = 28.75miles

Given that the standard deviation of the sample (S) = 3.4 miles

Degrees of freedom = n-1 = 64-1 =63

t₀.₀₅ = 1.9983

Step(ii):-

95% confidence interval for the population mean mileage is determined by

[tex](x^{-} - t_{0.05} \frac{S}{\sqrt{n} } , x^{-} + t_{0.05} \frac{S}{\sqrt{n} })[/tex]

[tex](28.75-1.99\frac{3.4}{\sqrt{64} },28.75 + 1.99 \frac{3.4}{\sqrt{64} } )[/tex]

(28.75 - 0.845 , 28.75 + 0.845)

(27.917 , 29.593)

Step(iii):-

98% confidence interval for the population mean mileage is determined by

[tex](x^{-} - t_{0.02} \frac{S}{\sqrt{n} } , x^{-} + t_{0.02} \frac{S}{\sqrt{n} })[/tex]

[tex](28.75-2.3824\frac{3.4}{\sqrt{64} },28.75 + 2.3824 \frac{3.4}{\sqrt{64} } )[/tex]

(28.75 - 1.01252 , 28.75 + 1.01252)

(27.737 , 29.762)

Final answer:-

98% confidence interval for the population mean mileage is

(27.737 , 29.762)

Assume we cut the last piece of the pie into two sections (1 and 2) along ray BD

such that m∠ABD = 2x+3, m∠CBD = 4x+7, and m∠ABC = 40°. Based on this information,

would you ask for section 1 or section 2 (you have to pick one) for dessert? Provide numerical

evidence to back up your choice. Explain your reasoning and your methods.

Answers

Answer:

Section 2

Step-by-step explanation:

I will pick the section with the largest angle.

Let's determine the size of the angle of each section.

Given:

m∠ABD = 2x+3,

m∠CBD = 4x+7,

m∠ABC = 40°

Thus:

m<ABD + m<CBD = m<ABC (angle addition postulate)

Substitute

2x + 3 + 4x + 7 = 40

Add like terms

6x + 10 = 40

6x + 10 - 10 = 40 - 10

6x = 30

6x/6 = 30/6

x = 5

✔️m∠ABD = 2x+3

Plug in the value of x

m<ABD = 2(5) + 3 = 13° (section 1)

✔️m∠CBD = 4x+7

m∠CBD = 4(5) + 7

m∠CBD = 27° (section 2)

✅I will pick section 2 because it is the section with the largest angle, which means it is the biggest.

What are the center and radius of a circle whose equation is:

(x−A)2+(y−B)2=C
Question options:

a)

Center: (−A,−B), radius = C

b)

Center: (−A,−B), radius =C −−√

c)

Center: (A, B), radius = C

d)

Center: (A, B), radius =C −−√

Answers

Answer:

d)

Step-by-step explanation:

Equation of circle with center at point (h, k) and radius, r.

[tex] (x - h)^2 + (y - k)^2 = r^2 [/tex]

This problem:

(x − A)^2 + (y − B)^2 = C

The center is (A, B).

The radius is sqrt(C).

Answer: d)

find the value for x y and z

Answers

Answer:

All triangles add up to 180 degrees so...

180 - 43 - 59 = 78 degrees.

So x - 78 degrees.

x and y are supplementary angles so...

180 - 78 = 102.

So y = 102.

180 - 102 - 49 = 29 degrees

So z = 29 degrees

Hope this helps!

Mandy and Randy are each playing with a beach ball. Mandy's ball has a diameter of 12 inches. Randy's ball has a diameter that is twice as large as Mandy's ball. How much larger is the volume of Randy's ball? Show and explain your reasoning.

Answers

Answer:

Randy's ball is 904.78 larger than Mandy's.

Step-by-step explanation:

Using math, we find that Mandy's ball is 904.78 inches in volume and if Randy's is twice the size that's, 904.78 x 2 = 1809.56. so Randy's ball is 904.78 larger than Mandy's

Name two pairs of adjacent angles and two pairs of vertical
angles in the figure.

Answers

Answer:

1. adjacent: ∠ACB and ∠BCD.

vertical: ∠ACB and ∠ECDStep-by-step explanation:

Rachel cut a whole banana into 6 pieces and then ate all the pieces. She put a point on a number line to show how much she ate.
0
Which fraction is equal to the point shown on the number line?

Answers

1/1????????????? maybe

z(x) is a function as defined below:

z(x) = x + 1

If you input a 3 into z(x), what do you get for the output?

Answers

3x+3 is the correct answer

Tina has eight packs of paper each of her packs contain 50 sheets. Caz has three packs of paper each of his packs contain 125 sheets. Juan has 350 sheets of paper which statement is true

Answers

Answer:

i think the question is incomplete but

Tina at an average contains each package of

50 sheets ÷ 8 pack

6.205 of sheet in each pack

125 sheets ÷ 3 packs

caz contain at average 41.60 sheet average

but where the juan packs of paper that's why question is incomplete


Miss Lin bought 40 raisin, butter and curry buns for a class party. The ratio
of the number of raisin buns to the number of butter buns to the number of
curry buns was 7:5:8. Find the number of curry buns Miss Lin bought.

Answers

Answer:

Number of curry buns is 16.

Step-by-step explanation:

Total number of buns =40.

Ratio of number of raisin buns to the number of butter buns to the number of curry buns = 7:5:8

Let number of raisin buns = 7X.

Let number of butter buns =5X.

Let number of curry buns = 8X.

Therefore,

7X+5X+8X = 40

20X = 40

X= (40/20) = 2.

Therefore number of curry buns =8X = 8×2 =16.

help me plissssss. “

Answers

Answer:

letter A because it's representing 100% plus some so it is increasing.

What is the value of x in the equation 4(2x + 12) = 0?

−8
−6
6
8

Answers

Answer:

-6

Step-by-step explanation:

4(2x+12)=0

8x+48=0

8x=-48

x=-6

PLEASE HELP!!! ILL GIVE BRAINLIEST !! Which is the correct answer ?

Answers

Answer:

c

Step-by-step explanation:

Answer:

C) Corresponding Angles

Step-by-step explanation:

A corresponding angle is when two angles are occupying the same intersection. A vertical angle is B & C, and A & D.

Hope this helps!

The volume of a cylinder is 1761 square
centimeters and the height is 11
centimeters. Find the radius.

Answers

Answer:

7.14cm

Step-by-step explanation:

A yogurt costs 35p.
How many yogurts can be bought for three pounds?

Answers

Answer:

8 yogurts or it will be 1 yogurt

Step-by-step explanation:

Since practically you cannot purchase "0.57" parts of one yogurt 3 pounds (300 p) would allow you to purchase only 8 yogurts...

pls help help help help

Answers

Answer:

1  and 1/6

Step-by-step explanation:

Answer:

7/6

Step-by-step explanation:

Transfer 1/3 to 2/6 and add it with 5/6

Help me guyssssss skeks

Answers

Answer:

19

Step-by-step explanation:

|-8 -11|=19

Answer:

3

Step-by-step explanation:

when you have 2 negitives it makes a positive which cancelles it out and it equals 3

Which number rounds to 700 when rounded to the nearest hundred?​

Answers

Answer:

C.

Step-by-step explanation:

Hope this helps! have a great day!

Evaluate each expression for the given value(s) of the variables(s).

Answers

Answer:

9.  [tex] \frac{1}{10,000} = 0.0001 [/tex]

10. [tex] \frac{1}{81} [/tex]

Step-by-step explanation:

9. [tex] x^{-4} [/tex]

Evaluate when x = 10.

Substitute x = 10 into the expression

[tex] 10^{-4} [/tex]

Apply the negative exponent rule ([tex] a^{-n} = \frac{1}{a^n} [/tex])

Thus:

[tex] = \frac{1}{10^4} [/tex]

[tex] = \frac{1}{10^4} = \frac{1}{10,000} = 0.0001 [/tex]

10. [tex] 2a^{-1}b^{-3} [/tex]

Evaluate when a = 6 and b = 3

Substitute

[tex] (2*6^{-1})(3^{-3}) [/tex]

Apply the negative exponent rule

[tex] (2*\frac{1}{6})(\frac{1}{3^3}) [/tex]

[tex] (\frac{2}{6})(\frac{1}{27}) [/tex]

[tex] \frac{2*1}{6*27} [/tex]

[tex] \frac{1}{81} [/tex]

[tex]\huge{ \mathfrak{  \underline{ Answer }\:  \:  ✓ }}[/tex]

Question : 9

plugging the value of x as 10, we get

[tex]\longrightarrow\: \: x {}^{ - 4} [/tex]

[tex]\longrightarrow\: 10 {}^{ - 4} [/tex]

[tex]\longrightarrow \dfrac{1}{10 {}^{4} } [/tex]

[tex] \longrightarrow\dfrac{1}{10000} [/tex]

[tex]\longrightarrow0.0001[/tex]

Question : 10

plugging the value of

a as 6b as 3

[tex]\longrightarrow2 {a}^{ - 1} b {}^{ - 3} [/tex]

[tex]\longrightarrow2 \times 6 {}^{ - 1} \times 3 {}^{ - 3} [/tex]

[tex]\longrightarrow \dfrac{2}{6 \times 27} [/tex]

[tex]\longrightarrow \dfrac{2}{162} [/tex]

[tex]\longrightarrow \dfrac{1}{81} [/tex]

_____________________________

[tex] \\ \\ \mathrm{ ☠ \: TeeNForeveR \:☠ }[/tex]

Solve the system.
9x2 + 4(y - 2)2 = 36
x² = 2y

Answers

Answer:

[tex]x =2[/tex]

[tex]y =2[/tex]

Step-by-step explanation:

Given

[tex]9x^2 + 4(y - 2)^2 = 36[/tex]

[tex]x^2 = 2y[/tex]

Required

Solve

Substitute:  [tex]x^2 = 2y[/tex] in [tex]9x^2 + 4(y - 2)^2 = 36[/tex]

[tex]9*2y + 4(y-2)^2 = 36[/tex]

[tex]18y + 4(y-2)^2 = 36[/tex]

Open bracket

[tex]18y + 4[y^2-2y - 2y + 4] = 36[/tex]

[tex]18y + 4[y^2-4y + 4] = 36[/tex]

Open bracket

[tex]18y + 4y^2-16y + 16 = 36[/tex]

Collect like terms

[tex]4y^2+18y-16y + 16 - 36 = 0[/tex]

[tex]4y^2+2y-20= 0[/tex]

Divide through by 2

[tex]2y^2+y-10= 0[/tex]

Expand

[tex]2y^2+5y - 4y-10= 0[/tex]

Factorize

[tex]y(2y + 5) - 2(2y + 5) = 0[/tex]

Factor out 2y + 5

[tex](y -2)(2y + 5) = 0[/tex]

Split

[tex]y - 2 =0\ or\ 2y + 5 = 0[/tex]

Solve for y

[tex]y =2 \ or\y = -\frac{5}{2}[/tex]

We have:

[tex]x^2 = 2y[/tex]

Make x the subject

[tex]x = \sqrt{2y[/tex]

The above is true for positive y values.

So: [tex]y =2[/tex]

This gives

[tex]x = \sqrt{2*2[/tex]

[tex]x = \sqrt{4[/tex]

[tex]x =2[/tex]

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