Bottles of popular cola drinks are supposed to contain 300ml of cola. There is some variation from bottle to bottle because the filling mackinery is not perfectly precise. the distribution fo the contents is normal with SD=3ml. The result of the average is 299.03. Is this convincing evidence that the mean contents of cola bottles is less than the advertised 300ml?(Find the z) A coin is tossed 10 times. What is the chance of observing 6 heads? Find the area under the x^2 curve with 10 degrees of freedom from the right of 4.86. A die is rolled 1296 times and lands on heads 650 times. Find the Z-value if it was expected to land on heads 600 times. A sample of 1,000 from a university says that 59% of students live on campus while 41% live off campus. Range from _____ to _____ is a 95% confidence interval for the students who live off campus. Scientist found orange juice helps reduce heart disease. People don't drink orange juice have 80% chance of heart disease. People who drink orange juice have 65% in a sample of 100 and SD = 4.1 Null hypothesis says orange juice doesn't help. The ave test score of students is 60. A sample of five students has ave test score of 75 with help of tutors. SD = 3.2 Null hypothesis : tutor doesn't help, ave score is still 60 In a sample of 40, ave age in 12th grade of school A = 17 SD = 0.2 In a sample of 20, ave age in 12 th grade of school B = 19 SD = 0.5 What is the SE for difference? What is the SE for a box with 60 red marbles, and 90 blue ones The average weight of the girls in the high school is 130lbs, and the SD is 30. Their average height is 70 inches, and the SD is 3. r=0.48 For a person who weight 148lbs will probably have height of __? The following distribution is given: Ave x=185 SDx=80 Ave y=120 SDy=45 r=-.75 Suppose y=170. What is the regression estimate for predicting the value of x from that of y? There has been a study which relates the scores of math and biology classes. The results of average test scores and SD's for each class are as follows: Ave Math score - 65 Ave Biology score - 70 SD - 5 SD - 10 r - .6 If a student has an average score of 70 in math, predict his biology score. In our Math 108 class the midterm scores average was about 55 with an SD of 20, as do scores on the final. The correlation between midterm scores and final scores is about 0.75. Estimate the average final score for the students whose midterm scores were 75. A study was done in Rye High School for the heights and weights of girls at the age of 16. The average weight was 110lbs with an SD of 10lbs and the average height was 64 inches with an SD of 2 inches. The correlation coeficient is 0.80. Predict the weight for a 16 year old girl whose height is 70 inches. The correlation between mid term and final is 0.8. The scatter diagram is football-shaped. Predict the percentile rank on the final for people rank 95% on mid term. A survey was conducted to estimate the correlation between teen Weed- Smokers and teen Tabacco- Smokers. The Weed- Smoker, puffed, on average 10 Weed- cigarettes per week with an SD of 2.Tabacco - Smokers smokes an average of 60 cigarettes per week with an SD of 5. Estimate the average Tabacco - Cigarettes smoked per week for a teen who smokes 12 Weed- Cigarettes. The correlation coefficient is 0.7. In a football- shaped diagram, for values X under 140 what is the percent of Y over 120? Use the following information. AveY=100,SDY=9. AveX=150,SDX=20. r=0.7. If r=0.5 for expected salary and educational level, what is the expected salary for people at the average educational level. salary avg=30,000, SD=10,000. educational level=12 yrs, SD=4 yrs. |

Last modified: Wed May 13 12:29:11 EDT 1998