Answer the Following Question

1.

Susan Sound predicts that students will learn most effectively with a constant background sound, as opposed to an unpredictable sound or no sound at all. She randomly divides twenty- fonr students into three groups of eight. All students study a passage of text for 3t] minutes. Those in group 1 study with hackgromd sound at a constant volume in the background. Those in group 2 study with noise that changes volume periodically. Those in group 3 study with no sound at all. After studying, all students take a It] point multiple choice tests over the material. Their scores are as follow: 1. Constant Sound \"unit-nun ------I-l- -----l--- At or 2 [lbs , what conclusion can Susan Sound made? A reeearoher wishes to eatimate the average amount of money a person spends on lottery,r tickets each month. A sample of 50 people 1who plag.r the lottery found the mean to be $19 and the standard deviation to be 6.3. Find the 95% oondenee interval of the population mean. A lecturer wishes te see whether the variatien in scares [mathematics subject) of the 23 students in her class is less than the variance cf the pepulaticn. The variance of the class is 193. Is there eneugh evidence to support the claim that the variation at" the student's scare is less than the papulatien variance [52:255) at a=_5? Assume that the scares are annually distributed