Question

In the midst of labor-management negotiations, the president of a company argues that the company’s blue-collar workers, who are paid an average of $43,000 per year, are well paid because the mean annual income of all blue-collar workers in the country is less than $43,000. That figure is disputed by the union, which does not believe that the mean blue-collar income is less than $43,000. To test the company president’s belief, an arbitrator draws a random sample of 225 blue-collar workers from across the country and asks each to report his or her annual income. The sample mean annual income of the 225 randomly selected blue-collar workers was $43,318. Assume that the population standard deviation is $5,000. Can it be inferred at the 5% significance level that the company president is correct?

1. To test:
H_{o}: (Click to select)x¯αpβμ = vs.
H_{a}: (Click to select) x¯μ β αp (Click to
select)><=≥≤≠

2. Test Statistic (Round to 3 decimals): z =

3. *p*-value
(Round to 3 decimals):

Conclusion: At α = ,
(Click to select)reject Hado not reject Hodo not reject Hareject Ho
since *p*-value (Click to select)><= α. We have (Click
to select)sufficientinsufficient evidence to conclude that the
(Click to select)sample meanpopulation variancesample proportion of
thepopulation proportion of thepopulation meansample variance
annual income of blue-collar workers (Click to select)is less
thanis greater thanis equal todiffers from dollars.

Therefore, there (Click to select)is notis enough evidence to infer that the company president is (Click to select)incorrectcorrect

Answer #2

1)

H0 : mu = 43000

Ha: mu < 43000

2)

xbar = 43318 ,sigma = 5000 , n = 225

z = (xbar -mu)/(sigma/sqrt(n))

= ( 43318 - 43000)/(5000/sqrt(225))

= 0.954

3)

p value = P(z< 0.954)

p value = 0.8300

at alpha 0.05 do not reject H0 since p value> 0.05

We have insufficient evidence to conclude that the the mean annual income of all blue-collar workers in the country is less than $43,000.

There is not enough evidence to infer that the company president is less than 430000

answered by: anonymous

A machine that is programmed to package 18.7 ounces of cereal in
each cereal box is being tested for its accuracy. In a sample of 43
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significance level that the machine is not working properly? That
is, can you conclude that the machine is either underfilling or
overfilling the cereal boxes?
1. To test: Ho: (Click to
select) β μ p x¯ α (Click
to...

Employees of a certain company took a mean of 6.8 vacation days
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number of sick days was less than 6.8. A sample of 52 employees
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α = 0.02, test the CEO’s claim.
a 1-6) Give the hypotheses for H0 (a1, a2 and
a3) and H1 (a4, a5 and a6)
H0...

How productive are U.S. workers? One way to answer this question
is to study annual profits per employee. A random sample of
companies in computers (I), aerospace (II), heavy equipment (III),
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profits per employee (units in thousands of dollars).
I
II
III
IV
27.5
13.8
22.1
17.6
23.1
9.5
20.3
16.8
14.3
11.3
7.7
14.3
8.9
8.3
12.5
15.1
11.1
6.1
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10.6
19.5
9.8
Shall we reject or not reject...

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