Question

In: Statistics and Probability

An instructor is grading tests for a class of 30 students. After the 29th student, the...

An instructor is grading tests for a class of 30 students. After the 29th student, the class mean is 51 and the class median is 81. the tests may be assumed to be in order from lowest to highest.

a. how is the distribution skewed?

b. what score must the 30th student get in order to raise the class average to 85.5?

c.after the 30th score is added to the group, the median rises to 82. What is the 16th score?

Solutions

Expert Solution


Related Solutions

If grading times are independent and the instructor begins grading at 6:50 P.M. and grades continuously
There are 40 students in an elementary statistics class. On the basis of years of experience, the instructor knows that the time needed to grade a randomly chosen first examination paper is a random variable with an expected value of 6 min and a standard deviation of 6 min. a. If grading times are independent and the instructor begins grading at 6:50 P.M. and grades continuously, what is the (approximate) probability that he is through grading before the 11:00 P.M. TV...
An instructor who taught two sections of MTH132, with 20 and 30 students respectively. The instructor...
An instructor who taught two sections of MTH132, with 20 and 30 students respectively. The instructor randomly select 15 students for a field trip. 1. What is the chance that exactly 10 of them are from the 2nd section? 2. What is the chance that at least 10 of them are from the 2nd section? 3. What is the chance that at least 10 of them are from the same section?
An instructor is interested in assessing students' typing speed in the class. He knows that the...
An instructor is interested in assessing students' typing speed in the class. He knows that the average at the university is 49 word per minute (wpm) with a SD of 18 wpm. He collects data from 31 of his students. a) What is the probability of the average typing speed being less than 49 wpm? probability =   b) What is the proability of the average typing speed being between 51 and 53 wpm? probability =   Note: Do NOT input probability...
A teacher has five students who have taken four tests. The teacher uses the following grading...
A teacher has five students who have taken four tests. The teacher uses the following grading scale to assign a letter grade to a student, based on the average of his or her four test scores. -------------------------------------------------------------------- Test Score Letter Grade -------------------------------------------------------------------- 90 – 100 A >= 80 < 90 B >= 70 < 80 C >= 60 < 70 D < 60 F ------------------------------------------------------------------- Write a program that uses Python List of strings to hold the five student names,...
A first-year accounting student is confused by a statement made in a recent class. The instructor...
A first-year accounting student is confused by a statement made in a recent class. The instructor stated that assets listened in the balance sheet of IBM Corporation include computers that are classified as current assets as well as computers that classified as long-term (noncurrent) assets. In addition, the instructor stated that investments in equity securities of other corporations could be classified in the balance sheet as either current or long-term assets. Explain to the student the distinction between current and...
In a student community, 30% of the students own a car and 50% of the students...
In a student community, 30% of the students own a car and 50% of the students who own a car also own a bicycle. Also, 60% of the student community own a bicycle. Furthermore 25% of students who own a bicycle, also own a two-wheeler. Car owners do not own two-wheelers. Finally, 30% of the students own a two-wheeler. What is the probability that a randomly selected student (a) owns a bicycle and a two-wheeler? (b) owns a car, but...
The instructor of a class offers his students a choice. Their final grade may be calculated...
The instructor of a class offers his students a choice. Their final grade may be calculated in one of two ways, which they must decide on as a class. The class has a total of 500 pts available. The 29 students in the class have a mean score of 407 pts, a standard deviation of 15 and a median score of 420. Option 1 is to have the grades based solely on the percentage of total points possible in the...
As part of a class exercise, an instructor at a major university asks her students how...
As part of a class exercise, an instructor at a major university asks her students how many hours per week they spend on social networks. She wants to investigate whether time spent on social networks differs for male and female students at this university. The results for those age 21 or under were: Males: 5, 7, 9, 10, 12, 12, 12, 13, 13, 15, 15, 20 Females: 5, 7, 7, 8, 10, 10, 11, 12, 12, 14, 14, 14, 16,...
An instructor from the school of business samples the students in his introduction to business class...
An instructor from the school of business samples the students in his introduction to business class to learn about the amount of dollars students spend per semester on textbooks. The distribution that follows indicates the results of his sample. SHOW WORK. Textbook Costs per Student per Semester (in dollars) 65, 147, 171, 142, 153, 187, 195, 106, 127, 178, 178, 205, 175, 178, 133, 186, 55 a) Construct a Box-and-Whisker Plot b) Calculate the interquartile range c) Determine if there...
The instructor claims that the average age of his students is 30 years old. To test...
The instructor claims that the average age of his students is 30 years old. To test this claim a sample of 33 students is taken. At an alpha level of .05 is there enough evidence to support this instructors claim? Sample ages: 32,28,24,18,35,41,27,28,28,31,27,25,28,31,35,40,36,32,29,28,19,21,26,24,21,19,27,26,23,27,30,20,21 Please list null and alternate hypothesis, critical value, test value, and all steps towards rejecting or accepting the null hypothesis.
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT