Aschool principal wants to observe how classroom area has an effect on classroom learning. the principal randomly chooses a group of students of the same age and grade, and places them in a classroom with an area of 400 square feet. the test scores of the class are recorded and analyzed at the end of the semester. how could this observation be changed into a valid experiment of the effects of classroom area? a. by including a classroom of identical area but a different shape b. by including an identical classroom with students in a different grade c. by including an identical classroom with a smaller number of students d. by including a classroom with movable walls

Can somebody 1. what is the formula for finding the vertical distance between two points on a coordinate plane?

Find the axis symmetry of x y=4x-6x+3

Overproduction of uric acid in the body can be an indication of cell breakdown. this may be an advance indication of illness such as gout, leukemia, or lymphoma.† over a period of months, an adult male patient has taken nine blood tests for uric acid. the mean concentration was x = 5.35 mg/dl. the distribution of uric acid in healthy adult males can be assumed to be normal, with σ = 1.87 mg/dl. (a) find a 95% confidence interval for the population mean concentration of uric acid in this patient's blood. what is the margin of error? (round your answers to two decimal places.) lower limit upper limit margin of error (b) what conditions are necessary for your calculations? (select all that apply.) σ is unknown n is large σ is known normal distribution of uric acid uniform distribution of uric acid (c) interpret your results in the context of this problem. there is not enough information to make an interpretation. the probability that this interval contains the true average uric acid level for this patient is 0.05. the probability that this interval contains the true average uric acid level for this patient is 0.95. there is a 95% chance that the confidence interval is one of the intervals containing the population average uric acid level for this patient. there is a 5% chance that the confidence interval is one of the intervals containing the population average uric acid level for this patient. (d) find the sample size necessary for a 95% confidence level with maximal margin of error e = 1.10 for the mean concentration of uric acid in this patient's blood. (round your answer up to the nearest whole number.) blood tests