Statistics II20815 marksNumerical: hypothesis test meanone sample tests for mean of normal population
The mean drying time of a brand of spray paint is known to be 122 seconds. The research division of the company that produces this paint contemplates that adding a new chemical ingredient to the paint accelerate the drying process. To investigate this conjecture, the paint with the chemical addition
The mean drying time of a brand of spray paint is known to be 122 seconds. The research division of the company that produces this paint contemplates that adding a new chemical ingredient to the paint accelerate the drying process. To investigate this conjecture, the paint with the chemical additions is sprayed on 50 surfaces and the drying time is recorded. The mean and standard deviation of drying time computed from these recorded are found as 116 seconds and 16.8 seconds respectively. Does these data provide strong evidence that the mean drying time is reduced by the addition of the new chemical? Use 5% level of significance. Also find p-value. [5]
- Population (claimed) mean: $\mu0 = 122$ seconds - Sample size: $n = 50$ - Sample mean: $\bar{X} = 116$ seconds - Sample standard deviation: $s = 16.8$ seconds - Significance level: $\alpha = 0.05$ - $H0: \mu = 122$ (no reduction) - $H1: \mu < 122$ (drying time reduced) - left-tailed test Since ...