On the SAT exam, a total of 25 minutes is allotted for students to answer 20 math questions without the use of a calculator. A guidance counselor would like to know if the students in his school are prepared to complete this portion of the exam in the time allotted. To investigate, the counselor selects a random sample of 35 students and administers this portion of the test. The students are instructed to turn in their test as soon as they have completed the questions. The mean amount of time taken by the students is 23 point 5 minutes with a standard deviation of 4 point 8 minutes. The counselor would like to know if the data provide convincing evidence that the true mean amount of time needed for all students of this school to complete this portion of the test is less than 25 minutes and therefore tests the hypotheses ratio of cap h sub 0 to mu is equal to 25 versus ratio of cap h sub A to mu is less than 25 , where mu is equal to the true mean amount of time needed for students of this school to complete this portion of the exam. The conditions for inference are met. The test statistic is t is equal to negative 1 point 8 5 and the cap p -value is between 0 point 0 2 5 and 0 point 0 5 What conclusion should be made at the significance level, alpha is equal to 0 point 0 1 ?
From previous experience, the owner of an apple orchard knows that the mean weight of Gala apples is 140 grams. There has been more precipitation than usual this year. The owner believes the weights of the apples will be heavier than usual and therefore the crop will be more profitable. The owner takes a random sample of 30 apples and records their mean weight. What is a Type II error in this situation?
A refrigeration unit at a restaurant is supposed to be kept at 40 times degree F An inspector would like to test the hypotheses ratio of cap h sub 0 to mu is equal to 40 versus ratio of cap h sub A to mu is not equal to 40 where μ= the true mean temperature for all times of the day. A 98 percent confidence interval based upon a random sample of 40 temperatures is 40 point 5 degrees to 42 point 1 degrees. Using the interval, what decision should be made?
Assuming the conditions for inference have been met, is there evidence of a difference, on average, in typing accuracy while wearing a blindfold and not wearing a blindfold? Use a significance level of A is equal to 0 point 0 5 Use the t -table.
Did you find these answers helpful?