OBLEM #1 1. A cosmetics company claims that teenage ladies consume an average of 150 php monthly for cosmetic products. To verify this claim, a researcher conducted a survey to 40 teenage ladies and found that their mean monthly expense for cosmetic products is 146 php with standard deviation of 12 php. Using a = 0.05, test whether the company's claim is realistic or not? :ps: 1. Describe the population parameter of interest. 2. Formulate the null and alternative hypothesis. 3. Check the assumptions. 4. Choose a significance level size for c.6. State the decision rule for rejecting or not the null hypothesis. 7. Compare the computed test statistic and the critical value/s