Ask a Question
  
  
  
Top Posters
Since Sunday
13
12
11
10
10
10
10
10
10
10
9
9
New Topic  
wrote...
Express Lane Plus
Posts: 357
Rep: 0 0
2 months ago
The average time spent sleeping​ (in hours) for a group of medical residents at a hospital can be approximated by a normal​ distribution, as shown in the graph to the right. Answer parts​ (a) and​ (b) below.
Attached file
Thumbnail(s):
You must login or register to gain access to this attachment.
Read 78 times
4 Replies
Replies
wrote...
Staff Member
2 months ago
a)
1.645 = (X - 6.1)/1
X = 1.645 + 6.1
X = 7.745 or 7.75 on rounding to 2 dps
Shortest sleeping time that place a resident in the top 5% of is 7.75 hours


b)Between what two values does the middle 50% of the sleep times lie?


The z values concerned are - 0.675 and + 0.675
- 0.675 = (X - 6.1)/1
X = 6.1 - 0.675
X = 5.425

or 5.43+ 0.675 = (X - 6.1)/1
X = 6.1 + 0.675
X = 6.775 or 6.78
Middle 50% sleep times lie between 5.43 hours and 6.78 hours
Thank you for using Biology-Forums.
wrote...
Express Lane Plus
2 months ago
a) 1.645 = (X - 6.1)/1 X = 1.645 + 6.1 X = 7.745 or 7.75 on rounding to 2 dps Shortest sleeping time that place a resident in the top 5% of is 7.75 hours b)Between what two values does the middle 50% of the sleep times lie? The z values concerned are - 0.675 and + 0.675 - 0.675 = (X - 6.1)/1 X = 6.1 - 0.675 X = 5.425 or 5.43+ 0.675 = (X - 6.1)/1 X = 6.1 + 0.675 X = 6.775 or 6.78 Middle 50% sleep times lie between 5.43 hours and 6.78 hours
it was incorrect !!!!!!
Answer accepted by topic starter
wrote...
Educator
Top Poster
Posts: 23921
2 months ago Edited: 2 months ago, bio_man
Sign in or Sign up in seconds to unlock everything.
a) 1.645 = (X - 6.1)/1 X = 1.645 + 6.1 X = 7.745 or 7.75 on rounding to 2 dps Shortest sleeping time that place a resident in the top 5% of is 7.75 hours

I'm not certain if "TOP 5" means 0.95 = z or 0.05 = z, that is, if they want the 95th percentile OR 5th percentile.

This will give you different answers. I'm assuming they want the 95th percentile, so choose the larger of the 2, 7.64.

You haven't uploaded question (b).

Please upload it when you get a chance, and I'll be around to answer more questions over the weeked Smiling Face with Open Mouth

Attached file
Thumbnail(s):
You must login or register to gain access to this attachment.
1
The best way to say thank you is with a positive review:

  https://trustpilot.com/review/biology-forums.com 

Your support goes a long way!


Make a note request here
Related Topics
wrote...
Educator
2 months ago
b)Between what two values does the middle 50% of the sleep times lie?

Where did you find this question?
The best way to say thank you is with a positive review:

  https://trustpilot.com/review/biology-forums.com 

Your support goes a long way!


Make a note request here
New Topic      
Explore
Post your homework questions and get free online help from our incredible volunteers.
Learn More
Improve Grades
Help Others
Save Time
Accessible 24/7
  137 People Browsing
 109 Signed Up Today
Related Images
 1680
 57
 12
Your Opinion
Who's your favorite biologist?
Votes: 30