Researchers are interested in the mean age of a certain population. A random sample of 10 individuals drawn from the population has a mean of 27. Assuming that the population is approximately normally distributed with variance 20, can we conclude that the mean is different from 30 years? The significance level $\alpha = 0.05$. The p-value is given as 0.0340. The question asks how we can use the p-value in making a decision.
Probability and StatisticsHypothesis TestingP-valueStatistical SignificanceNormal DistributionMeanVariance
2025/4/13
1. Problem Description
Researchers are interested in the mean age of a certain population. A random sample of 10 individuals drawn from the population has a mean of
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7. Assuming that the population is approximately normally distributed with variance 20, can we conclude that the mean is different from 30 years? The significance level $\alpha = 0.05$. The p-value is given as 0.
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0. The question asks how we can use the p-value in making a decision.
2. Solution Steps
The problem describes a hypothesis test to determine if the population mean is different from 30 years. We have a sample mean, sample size, and population variance. The null and alternative hypotheses are:
The significance level is .
The p-value is given as .
In hypothesis testing, we compare the p-value to the significance level . If the p-value is less than or equal to , we reject the null hypothesis. If the p-value is greater than , we fail to reject the null hypothesis.
In this case, we compare to .
Since , we reject the null hypothesis .
This means that there is sufficient evidence to conclude that the population mean is different from 30 years.
3. Final Answer
Since the p-value (0.0340) is less than the significance level (0.05), we reject the null hypothesis. We conclude that the population mean is different from 30 years.