statistics
posted by stan .
5. A professor teaching introductory psychology gave the grades that follow. According to the normal curve, she should have given about 4% A’s, 14% B’s, 64% C’s, 14% D’s, and 4% F’s. Do a ChiSquare to determine if the actual grade assignment significantly departed from the normal distribution. α=.05
A’s B’s C’s D’s F’s
25 35 60 30 20

X^2 = ∑ (OE)^2/E, where O = observed frequency and E = expected frequency.
∑ = sum of all the cells.
E = (column total * row total)/grand total
df = n  1, where n = number of cells
Look up value in X^2 table in the back of your textbook.
Respond to this Question
Similar Questions

college
Suppose that, for a certain exam, a teacher grades on a curve. It is known that the grades follow a normal distribution with a mean of 70 and a standard deviation of 7. There are 45 students in the class. How many students should receive … 
Statistics
A fair 20sided die is rolled 60 times, and the value of chisquare is computed using expected counts of 3 for each face. If this process is repeated many times, the shape of the distribution of the values of chisquare should be... … 
Business Statistics
In each case, sketch the two speciﬁed normal curves on the same set of axes: a A normal curve with m 20 and s 3, and a normal curve with m 20 and s 6. b A normal curve with m 20 and s 3, and a normal curve with m 30 and s 3. … 
statistics
Using the definition of recovery provided in W1: Assignment 5, determine how many participants recovered at the end of posttreatment and use a chisquare analysis to compare recovery rates across the three treatments at both posttreatment … 
statistics
Percentage grades in a large physics class follow a normal distribution with mean 58. It is known that 3% of students receive grades less than 39.2. What is the standard deviation of grades in the class? 
statistics
A professor is interested in the relationship between the number of hours students study for a quiz and their quiz grades. She asked each student to record the number of hours that he/she studied for the final exam. She also recorded … 
statistics
A professor is interested in determining whether assigning mandatory homework affects students’ grades. He is currently teaching two sections of the same class; in one class, he assigns mandatory homework problems, while in the second … 
Psychological Statistics
A professor records scores from a fivepoint quiz for each student in an introductory psychology class. If the data were presented in a frequency distribution graph, what type of graph should be used? 
statistics(business)
Large group of students took a test in English and the final grades have a mean of 75 and a standard deviation of 8. If we can approximate the distribution of these grades by a normal distribution. What percentage of the students (ii) … 
statistics
Large group of students took a test in English and the final grades have a mean of 75 and a standard deviation of 8. If we can approximate the distribution of these grades by a normal distribution. What percentage of the students (ii) …