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:
H0:μ=30H_0: \mu = 30
H1:μ30H_1: \mu \neq 30
The significance level is α=0.05\alpha = 0.05.
The p-value is given as p=0.0340p = 0.0340.
In hypothesis testing, we compare the p-value to the significance level α\alpha. If the p-value is less than or equal to α\alpha, we reject the null hypothesis. If the p-value is greater than α\alpha, we fail to reject the null hypothesis.
In this case, we compare p=0.0340p = 0.0340 to α=0.05\alpha = 0.05.
Since 0.03400.050.0340 \leq 0.05, we reject the null hypothesis H0H_0.
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.

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