Summary Key ofldeos A hypothesis is a tentative statement or explanation of a phenomenon. It is a conjecture or assertion about a parameter. A null hypothesis is a statement that there exists a difference between a parameter and a specific value. An alternative hypothesis is a statement that there exists a difference between a parameter and a specific value. If the alternative hypothesis is expressed, using "not equal to\" symbol (at), if then the test is two-toiled or nondirectionol. Directions. A. Identify whether the following is a null hypothesis or an alternative hypothesis. 1. The average age of grade eleven students is 17 years old. 2. The mean content of citric acid on a bottle ofjuice drinks is greater than 2 ml. 3. The average monthly salary of private school teachers is less than F16 000. 4. The mean weight of newborn babies is 0.5 kg. 5. The average IQ of grade eleven students is less than 108. B. For each of the foII0wing conjecture, state the null {Ho} and the alternative hypotheses (Ha). 1. The average time to commute from home to school is 35.9 minutes. 2. The average number of vehicles passing through NLEX daily is less than 21 000. 3. The average daily number of customers in a convenient store is less than 1 025. 4. The mean content of citric acid in a bottle ofjuice drinks is greater than 2ml. 5. The average typing speed of a secretary is 23.8 words per minute. ASIAN INSTITUTE OF COMPUTER STUDIES (AICS) Activity 2: Test and Truth Directions. A. Identify the error (Type I or Type II) if there is any committed in each following situation. 1. A true null hypothesis is accepted. 2. A false null hypothesis is accepted. 3. A true null hypothesis is rejected. 4. A false null hypothesis is rejected. B. True or False 1. If the rejection region lies entirely on the left tail of the sampling distribution, then the test is a two-tailed test. 2. The probability of committing Type I error is called the level of significance. 3. In a test of hypothesis, a test statistic is computed from the sample data. 4. If we rejected the null hypothesis, at the a = 0.01, then we would also have rejected it at the a = 0.05. 5. A type l error is committed when we fail to reject the null hypothesis when it is actually true. 6. The level of significance is set during testing the hypothesis. 7. If the computed value falls outside the rejection region, then the null hypothesis is rejected. 8. If the symbol less than (