A company that manufactures light bulbs claims that its light bulbs last an aver
ID: 3218846 • Letter: A
Question
A company that manufactures light bulbs claims that its light bulbs last an average of 1150 hours. A sample of 25 light bulbs manufactured by this company gave a mean life of 1094 hours and a standard deviation of 174 hours. A consumer group wants to test the hypothesis that the mean life of light bulbs produced by this company is less than 1150 hours. The significance level is 5%. Assume the population is normally distributed. Does the data provide evidence to contradict the company’s claim about the average lifetime of their light bulbs? A. Yes B. No
Explanation / Answer
The statistical software output for this problem is:
One sample T hypothesis test:
: Mean of population
H0 : = 1150
HA : < 1150
Hypothesis test results:
Since p - value is greater than 0.05, we do not reject the null hypothesis.
Hence,
the data do not provide evidence to contradict the company’s claim about the average lifetime of their light bulbs
The answer is No.
Mean Sample Mean Std. Err. DF T-Stat P-value 1094 34.8 24 -1.6091954 0.0603Related Questions
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