Question

A manufacturer claims that the mean lifetime of its lithium batteries is less than 1200 hours. A homeowner randomly selects 35 of these batteries and finds the mean lifetime to be 1180 hours with a standard deviation of 80 hours. Test the manufacturers claim. Use α = 0.05.

Answer #1

solution

this is the left tailed test .

The null and alternative hypothesis is ,

H0 : = 1200

Ha : <1200

Test statistic = z

= ( - ) / / n

= (1180 - 1200) / 80 / 35

= -1.48

P(z < -1.48 ) = 0.0694

P-value = 0.0694

= 0.05

P-value >

do not Reject the null hypothesis .

There is no sufficient evidence to suggest that

A manufacturer claims that the mean lifetime of its lithium
batteries is 902 hours. A homeowner selects 25 of these batteries
and finds the mean lifetime to be 881 hours with a standard
deviation of 83 hours. Test the manufacturer's claim. Use α =
0.05.

A manufacturer claims that the mean lifetime of its lithium
batteries is less than 1500 hours. A homeowner selects 25 of these
batteries and finds the mean lifetime to be 1480 hours with a
standard deviation of 80 hours. Test the manufacturer's claim.
Use α = 0.10.
A.
P-value = 0.112 > 0.10; do not reject H0; There is not enough
evidence support the claim, that mean is less than 1500.
B.
P-value = 0.112 > 0.05; do not reject...

A manufacturer claims that the mean lifetime of its lithium
batteries is less than 1120 hours. A homeowner selects 25 of these
batteries and finds the mean lifetime to be 1100 hours with a
standard deviation of 75 hours. Test the manufacturer's claim.
Use α = 0.01.
A. P-value = 0.110 > 0.01; do not reject H0; There is not
enough evidence support the claim, that mean is less than 1120.
B. P-value = 0.097 > 0.01; do not reject...

A manufacturer claims that the mean lifetime of its lithium
batteries is less than 1520 hours. A homeowner selects 27 of these
batteries and finds the mean lifetime to be 1498 hours with a
standard deviation of 76 hours. Test the manufacturer's claim. Use
α = 0.10.
A. P-value = 0.112 > 0.02; do not reject H0; There is not
enough evidence support the claim, that mean is less than 1500.
B. P-value = 0.072 > 0.05; do not reject...

A manufacturer claims that the mean life time of its lithium
batteries is 1500 hours . A home owner selects 30 of these
batteries and finds the mean lifetime to be 1470 hours with a
standard deviation of 80 hours. Test the manufacturer's claim.
Use=0.05. Round the test statistic to the nearest thousandth.
a) Hypothesis:
b)Critical value (t critical):
c)Test statistic (tstat) and the decision about the test
statistic:(reject or fail to reject Ho):
d)Conclusion that results from the decision...

1. A manufacturer claims that the mean lifetime of its
fluorescent bulbs is 1500 hours. A homeowner selects 40 bulbs and
finds the mean lifetime to be 1480 hours with a population standard
deviation of 80 hours. Test the manufacturer's claim. Use alpha
equal to 0.05. State the sample mean and the population standard
deviation.
2. Using problem in number 1. Choose the correct hypotheses.
3. Using the problem in number 1. State the critical
value(s).
4. Using the problem...

A manufacture of car batteries claims its new batteries will
have a mean lifetime of 4 years. A random sample of 35 batteries
found the mean lifetime to be 3.91 years. If the population
standard deviation is known to be 0.22 years; is there enough
evidence, at the 0.05 significance level, to suggest the mean
lifetime is less than 4 years?.

A car manufacturer, Swanson, claims that the mean lifetime of
one of its car engines is greater than 220000 miles, which is the
mean lifetime of the engine of a competitor. The mean lifetime for
a random sample of 23 of the Swanson engines was with mean of
226450 miles with a standard deviation of 11500 miles. Test the
Swanson’s claim using a significance level of 0.01. What is your
conclusion?

1. A manufacturer claims that its rechargeable batteries are
good for an average 1,000 charges with a standard deviation of 25
charges. A random sample of 20 batteries has a mean life of 992
charges. Perform an appropriate hypothesis test with α = 0.05,
assuming the distribution of the number of recharges is
approximately normal. Hypothesis:
Test statistic:
p-value:
Conclusion:
Interpretation:

A battery company claims that its batteries last an average of
100 hours under normal use. After several complaints that the
batteries do not last this long, an independent testing laboratory
decided to test the company’s claim with a random sample of 42
batteries. The data from the 42 batteries appeared to be unimodal
and symmetric with a mean 97 hours and a standard deviation of 12
hours. Is this evidence that the company’s claim is false and these
batteries...

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 4 minutes ago

asked 4 minutes ago

asked 39 minutes ago

asked 45 minutes ago

asked 45 minutes ago

asked 45 minutes ago

asked 51 minutes ago

asked 56 minutes ago

asked 56 minutes ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago