The total precipitation in Normal City in January is approximately normally distributed with a mean of 3.2 inches, and a standard deviation of 0.69. A researcher claims that the standard deviation, σ, of the total March precipitation in recent years is less than 0.69. A random sample of 18 precipitation measurements from the last three decades is considered and the mean of these measurements is found to be 3.1 with a standard deviation of 0.45. Is there enough evidence to support the researcher's claim at the 0.1 level of significance?

  

Perform a one-tailed test. Then fill in the table below. Carry your intermediate computations to at leest three decimal places and round your answers as specified in the table. (If necessary, consult a list of formuias.) H, :0 The null hypothesis: ", :0 The alternative hypothesis: The type of test statistic: (Choose one The value of the test statistic: (Round to at least three decimal places.) The critical value at the 0.1 level of significance: (Round to at least three decimal places.) Can we support the claim that the standard deviation of the total March precipitation in recent Yes No years is less than 0.74?