Question

3. A coin mint has a specification that a particular coin has a mean weight of 2.5 g. A sample of 33 coins was collected. Those coins have a mean weight of 2.49616 g and a standard deviation of 0.01851 g. Use a 0.05 significance level to test the claim that this sample is from a population with a mean weight equal to.2.5 g.

Answer 1

Date: 21/05/2019 Answer To test the hypothesis is that the mean weight is not equal to 2.50 gram at 590 significance level The null and alternative hypothesis is, H 0 : μ-2.50 На: # 2.50 The t-test statistics is 2.49616 -2.50 0.01851//33 0.01851/33 --1.192 The t-test statistics is-1.192 The t-critical value is,

The sample size is small and two-tailed test. Look in the column headed α-005 and the row headed in the t distribution table by using degree of freedom is, 33-1 - 32 2.037 | The t-critical value is Decision The statistical decision is that the t-test statistics which is -1.192 is less than t-critical value which is-2.037, so the null hypothesis is not rejected at 5% level of significance. There is insufficient evidence to indicate that the mean weight is not equal to 2.50 gram The result is not statistically significant.