PSYCH 100A Lecture Notes - Lecture 8: Type I And Type Ii Errors, Null Hypothesis, Birth Weight
Document Summary
Average birth-weight for women living in poverty is mu= 2800 grams with sd= 500 grams. A local hospital introduced an innovative new prenatal care program to reduce the number of low birth-weight babies born in the hospital. Babies born to these women had a birth weight of xbar = 3075. Conduct a one-sample z-test on whether the new program is effective in raising birth weight in the population. Standard error: 500/ square root of 25 = 100. Z score: 3075-2800/ 100 (standard error) = 2. 75. So reject the null hypothesis, alpha = . 05 one tailed, it is possible that this is a. Type i error (rejecting the null when the null is actually true) Any null within the ci, fail to reject. All null in the ci, reject the null. D = raw effect size / standard deviation. 3075 -2800 = 275 grams (raw effect size)
