MATH STATS URGENT PLEASE HELP
Favorites|Homepage
Subscriptions | sitemap
HOME > > MATH STATS URGENT PLEASE HELP

MATH STATS URGENT PLEASE HELP

[From: ] [author: ] [Date: 11-12-23] [Hit: ]
If 330 students recieved a mark greater than 80 how many wrote the test?3)On a test Neil scored 81 while the class mean was 72 and the standard deviation was 15.Find the number of students who Neil bettered if 380 students wrote the test.-1.The student’s score, 8k – 16,......
Could you please show your work

1) The mean on a test is 5K with a standard deviation of k-2. A students score on a test is represented by 8k-16. If the students z-scores is 2, then calculate the students actual score.

2)The results of an exam were normally distributed with a mean of 65 and a standard deviation of 12. If 330 students recieved a mark greater than 80 how many wrote the test?

3)On a test Neil scored 81 while the class mean was 72 and the standard deviation was 15.Find the number of students who Neil bettered if 380 students wrote the test.

-
1.

z = (x – mean)/sigma
2 = ((8k – 16) – 5k)/(k – 2)
2k – 4 = 3k – 16
12 = k

The student’s score, 8k – 16, is 80.

2.

z = (x – mean)/sigma
z = (80 – 65)/12
z = 15/12
z = 1.2

This z-score equals or exceeds the scores of 88.49% of the test takers. That leaves 11.51% to score higher, which corresponds to the 330 students. Dividing then number of students by the percentage, 330/.1151, shows 2867 students took the test.

3.

z = (x – mean)/sigma
z = (81- 72)/15
z = 0.6

This z-score equals or exceeds the scores of 72.57% of the test takers. 380*.7257 = 275.76, so Neil’s score was better than 275 of the students who also took the test.
1
keywords: HELP,URGENT,MATH,STATS,PLEASE,MATH STATS URGENT PLEASE HELP
New
Hot
© 2008-2010 http://www.science-mathematics.com . Program by zplan cms. Theme by wukong .