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?
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
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?
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)
Helpp please… due at 12:00
Answer:alternate exterior angles
Step-by-step explanation:
Since they’re on the outside of the parallel lines that makes them exterior
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?
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.
if △ABC = △DEF, which side is congruent to EF?
A. AB
B. BC
C. AC
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 = FDhow can i solve the following
4(5x-2) = 2(9x + 3
pls i need this one n i pass the class pls pls help me
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
expand 3e(e+4)
Hhhhhhh
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] ✅
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[tex]3 \: e \: ( \: e + 4 \: ) \\ \\ = 3 \: e \times \: e + 3 \: e \times 4 \\ \\ = 3 \: {e}^{2} + 12 \: e[/tex]
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