Null hypothesis is defined as?

Null hypothesis is defined as?

• A. The hypothesis that there is no significant difference between specified populations, any observed difference due to sampling or experimental error
• B. The alternative hypothesis
• C. The actual observed difference
• D. The population mean equals zero

Answer: (A)

The null hypothesis is a default assumption that there is no real difference or effect between the populations or groups being studied. It holds that any observed difference comes from sampling variability or random error, not from a true underlying difference. In hypothesis testing, we use data to assess whether there is enough evidence to reject this default position in favor of the alternative hypothesis, which claims there is a real difference. The correct description fits this idea by stating there is no significant difference and that observed variation is due to sampling or experimental error. The other options point to different ideas: the alternative hypothesis asserts a real difference, the actual observed difference is data rather than a hypothesis, and a statement like the population mean equals zero is a specific claim about a parameter, not the general default assumption of no effect.

The null hypothesis is a default assumption that there is no real difference or effect between the populations or groups being studied. It holds that any observed difference comes from sampling variability or random error, not from a true underlying difference. In hypothesis testing, we use data to assess whether there is enough evidence to reject this default position in favor of the alternative hypothesis, which claims there is a real difference. The correct description fits this idea by stating there is no significant difference and that observed variation is due to sampling or experimental error. The other options point to different ideas: the alternative hypothesis asserts a real difference, the actual observed difference is data rather than a hypothesis, and a statement like the population mean equals zero is a specific claim about a parameter, not the general default assumption of no effect.