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

A + B + C = 4
step by step please​

Answers

Step-by-step explanation:

Let's solve for a.

a+b+c=4

Step 1: Add -b to both sides.

a+b+c+−b=4+−b

a+c=−b+4

Step 2: Add -c to both sides.

a+c+−c=−b+4+−c

a=−b−c+4

Answer:

a=−b−c+4

(hope this helped plz mark brilliant)

I need help with #3. Please help. I have to show all work so please explain

Answers

Answer:

a = 2

Step-by-step explanation:

Use Pythagorean Theorem:

[tex]a^2+b^2=c^2\\a^2+2.1^2=2.9^2\\a^2+4.41=8.41\\a^2=4\\\sqrt{a^2}=\sqrt{4}\\a=2[/tex]

Therefore, a is 2 meters.


in rectangle ABCD above,
1. How many opposite sides are equal?
2. Name the parallel opposite sides.
3. Name the opposite angles that are equal.
4. How many right angles can you identify?
5. Identify the equal opposite sides.
6. How many triangles can you identify?
7. Line AB and CD are adjacent to each other.
true or false?
8. the dotted lines AC andBD are called what?

Answers

Answer and Step-by-step explanation:

1. 2 pairs (aka 4 sides) of Opposite Sides are equal

2. AB and DC are parallel, and AD and BC are parallel  

3. Angles BDC and ACD are equal, angles DAC and DBC are equal, the angles ADB and BCD are equal, angles CAB and DBA are equal

4. 4 right angles

5. AB and DC are equal, and AD and BC are equal

6. 4 Triangles

7. False

8. Diagonals of a rectangle.

#teamtrees #PAW (Plant And Water)

please help picture included
Match the verbal expression (term) with its algebraic expression (definition). Match Term Definition Some number A) a = 2 increased by two A variable decreased B) b + 2 by two Product of an C) y2 unknown value and two D) X - 2 Quotient of some number and two An unknown value E) 22 squared​

Answers

9514 1404 393

Answer:

  B, D, E, A, C

Step-by-step explanation:

The main idea here is to use your English comprehension skill to determine the meaning of the phrase, then use your math understanding to write it in symbols. Turning off your brain at the sight of a "word problem" will not be productive.

The wording "some number" or "a variable" or "unknown value" all refer to a variable, typically represented by a single letter. Letters commonly use are {a, b, c, x, y, z}, but variables are not restricted to that set (nor to single letters, nor lower case letters).

In most cases, the math expression is a direct translation of the English expression using the usual math symbols. Values are generally increased by addition, decreased by subtraction, squared using an exponent of 2. A product is the result of multiplication, and a quotient is the result of division.

Top-to-bottom, the boxes on the left will be filled with B, D, E, A, C.

how can i solve the following
4(5x-2) = 2(9x + 3

Answers

20x-18x=6+8
2x=14
X=7
Answer

a + b = 300 pls help i cant find out the answer

Answers

Answer:

a= 250

b= 50

250 + 50 = 300

Step-by-step explanation:

There's many solutions but this was the first one I could come up with.

Answer:

my opinion is seince a+b=300 then the sqaure of 300= 17.3?

Step-by-step explanation:

Helpp please… due at 12:00

Answers

Answer:alternate exterior angles

Step-by-step explanation:

Since they’re on the outside of the parallel lines that makes them exterior

The correct answer is C. Alternate Exterior Angles

expand 3e(e+4)
Hhhhhhh

Answers

Answer:

[tex]3e^{2} + 12e[/tex]

Step-by-step explanation:

[tex]3ee+3e4[/tex]

[tex]3ee+3 * 4e[/tex]

[tex]3e^{2} + 12e\\[/tex]

[tex]3 \: {e}^{2} + 12 \: e[/tex] ✅

[tex]\large\mathfrak{{\pmb{\underline{\red{Step-by-step\:explanation}}{\orange{:}}}}}[/tex]

[tex]3 \: e \: ( \: e + 4 \: ) \\ \\ = 3 \: e \times \: e + 3 \: e \times 4 \\ \\ = 3 \: {e}^{2} + 12 \: e[/tex]

[tex]\large\mathfrak{{\pmb{\underline{\orange{Mystique }}{\orange{♡}}}}}[/tex]

if △ABC = △DEF, which side is congruent to EF?
A. AB
B. BC
C. AC

Answers

Answer:

BC

Step-by-step explanation:

BECAUSE BC IT'S EQUAL TO EF

Answer:

B. BC

Step-by-step explanation:

By SSS rule in ∆ ABC and DEF,

AB = DEBC = EFCA = FD

I will give BRAINLIEST to whoever answers correctly first!!!

Sophie wants to buy a pair of scissors that cost $1.82. If she gives the cashier a five dollar bill, how
much change should she get back?

Answers

$3.18

Explanation: I am a cashier hahaha

Answer:

Sophie will get $3.18 back in change.

Step-by-step explanation:

You do 5.00-1.82 and you get 3.18, which is equal to the change that Sophie will get.

Sadie and Connor both play soccer. Connor scored 2 times as many goals as Sadie. Together they scored 9 goals. Could Sadie have scored 4 goals? Why or why not?

Answers

Answer:

no

the goal total would be too high

Step-by-step explanation: If Sadie had scored 4 goals, Connor would have scored 2 times 4 = 8 goals. Their goal total would then be 4+8 = 12, not 9. Sadie cannot have scored 4 goals.

__

If we let s represent the number of goals Sadie scored, then 2s is the number Connor scored. Their total is ...

 s + 2s = 9

 3s = 9 . . . . . . collect terms

 s = 9/3 = 3 . . . divide by the coefficient of s

Sadie scored 3 goals. (s=4 is not the solution to the problem)

PLEASE HELP ME FAST I WILL GIVE BRAINLYEST

Answers

7.)

cbrt(1200)

10.63

8.)

sqrt(112)

10.58

Answer:

1.) because 10^3=1000 and 11^3 = around 1330  we know that the answer must fall between 10 and 11. Because they're pretty much equal distance I would estimate it to be around 10.5 (if you need an exact answer it's 2∛150)

2.) because 11^2=121 and 10^2= 100 we know that it must fall between 10 and 11. Because these are pretty much equal distance as well I would estimate it to be around 10.5 as well (if you need an exact answer it's 4√7)

Step-by-step explanation:

What is the area of this???

Answers

9.09(m2)??
I think so

What is the result of subtracting the second equation from the first

Answers

I didn’t undertand the question... mayb ur attachment isnt added! Plz check!

Instructions: Find the value of x
Please help

Answers

The two chords are the same length given by the 4 short lines through each section.

Because the chords are the same length they need to be equal distance from the center of the circle

X = 9

pls i need this one n i pass the class pls pls help me

Answers

9514 1404 393

Answer:

  x = 5

Step-by-step explanation:

The two triangles are similar by the ASA theorem. The ratio of long side to short side in each right triangle is the same:

  x/3 = 7.5/4.5

  x = 3(7.5/4.5) . . . . multiply by 3

  x = 5

Help me out plsssssss

Answers

120 the answer is 120

Answer:

125

Step-by-step explanation:

the bearing of b to a is equal to 85+45

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