Question

1. People were asked if there is solid evidence that the earth is getting warmer. Among 1500 respondents, 22% said that there is not such evidence. Use a 0.95 confidence level (0.01 significance level) to test the claim that less than 25% of the population believes that there is not solid evidence that the earth is getting warmer. a) (1 pts)VERIFY the requirements are satisfied b) (1 pts)CLAIM: (IN WORDS) c) (1 pts)CLAIM: (IN EQUATION FORM) d) (1 pts)DETERMINE THE HYPOTHESES: : Ho: H1: e) (2 pts DRAW THE DISTRIBUTION - LABEL THE CRITICAL VALUE(S) f) (2 pts)CALCULATE THE TEST STATISTIC and include the test statistic on the graph above.

Answer 1

The data are a simple random sample from the population. The population is atleast 10 times as large as the sample. The sample size is large enough that np, 210 and n(1-P) 210. Yes, the requirements are satisfied. CLAIM:

There is not solid evidence that the earth is getting warmer less than 25%. (c) CLAIM: H:1<0.25. Ho:1=0.25 H:1<0.25

P-Value=0.0036 test =-2.6833 2=-2.3263 The critical value is 26.01 = -2.3263. EXCEL (PH Stat) output:

Z Test of Hypothesis for the Proportion 0.25 Data Null Hypothesis is Level of Significance Number of Items of Interest Sample Size 0.01 330 1500 Intermediate Calculations Sample Proportion Standard Error Z Test Statistic 0.22 0.0112 -2.6833 Lower-Tail Test Lower Critical Value p-Value Reject the null hypothesis -2.3263 0.0036 The value of test statistic is Z=-2.6833. Reject H.

Conclusion: Therefore, there is not solid evidence that the earth is getting warmer less than 25%.