SpikeSpiegel
Badges: 2
Rep:
?
#1
Report Thread starter 6 years ago
#1
Hi there, my teacher went through this question in class, i didn't get a single thing. Please help!


b) The company fits a standby battery to its power supplies and has recently been experiencing problems with its life. The battery supplier claims that it should last for 200 hours under normal conditions as their tests show a mean life of 200 hours. The designer of the power supply is not convinced. A technician has tested 220 batteries for you and tabulated the results. The designer asks you to process them and to establish what the working life really is. Here are the figures.
Life (hrs) Number
190—192 46
192—194 15
194—196 26
196—198 25
198—200 28
200—202 27
202—204 24
204—206 12
206—208 8
208—210 5
210— 212 4










Calculate the measures of central tendency and feed your thoughts to the designer.
0
reply
gdunne42
Badges: 21
Rep:
?
#2
Report 6 years ago
#2
You could estimate the mean and standard deviation or you could interpolate the median.


Posted from TSR Mobile
0
reply
SpikeSpiegel
Badges: 2
Rep:
?
#3
Report Thread starter 6 years ago
#3
is that all? it says calculate the central tendency.. and feed the thoughts.. what exactly do they want?
0
reply
gdunne42
Badges: 21
Rep:
?
#4
Report 6 years ago
#4
(Original post by SpikeSpiegel)
is that all? it says calculate the central tendency.. and feed the thoughts.. what exactly do they want?
mean and median are measures of central tendency
standard deviation and inter quartile range are measures of spread
once you have calculated one of them, or both, you can comment on the battery makers claims about the mean life.
0
reply
SpikeSpiegel
Badges: 2
Rep:
?
#5
Report Thread starter 6 years ago
#5
ok ive calculated the measures of tendency.. which is mean and median! ... how do I comment on that?
0
reply
SpikeSpiegel
Badges: 2
Rep:
?
#6
Report Thread starter 6 years ago
#6
0
reply
gdunne42
Badges: 21
Rep:
?
#7
Report 6 years ago
#7
(Original post by SpikeSpiegel)
ok ive calculated the measures of tendency.. which is mean and median! ... how do I comment on that?
How do they compare with the claims made by the battery maker?

I have not done the calculations but it looks like the data is skewed so the median life is less than the mean.
If that's the case then typical battery life is less than the mean the manufacturer claims



Posted from TSR Mobile
0
reply
TeeEm
Badges: 19
Rep:
?
#8
Report 6 years ago
#8
(Original post by SpikeSpiegel)
what level is this work?
0
reply
SpikeSpiegel
Badges: 2
Rep:
?
#9
Report Thread starter 6 years ago
#9
BTEC level 3
0
reply
TeeEm
Badges: 19
Rep:
?
#10
Report 6 years ago
#10
(Original post by SpikeSpiegel)
BTEC level 3
are you meant to use confidence intervals?
0
reply
SpikeSpiegel
Badges: 2
Rep:
?
#11
Report Thread starter 6 years ago
#11
no?
0
reply
TeeEm
Badges: 19
Rep:
?
#12
Report 6 years ago
#12
(Original post by SpikeSpiegel)
no?
I do not know much about the level BTEC but

measures of central tendency are simply averages such as the mean and median

as data is grouped

then mean will be estimated by using the midpoints


the median will be estimated by a Cumulative frequency graphs or interpolation.

for video tutorials go to UTUBE and type

mean of grouped data
median of grouped data


Also look atPages 20 - 24 on the link

http://www.madasmaths.com/archive/ma...a_analysis.pdf

there some worked solution there.


hope these are useful
0
reply
Muttley79
Badges: 20
Rep:
?
#13
Report 6 years ago
#13
What was the mean? median?
0
reply
Muttley79
Badges: 20
Rep:
?
#14
Report 6 years ago
#14
Have you found the mean and median? How do they compare to the '200 hours' in the question?
0
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
Back
to top
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

Do you think receiving Teacher Assessed Grades will impact your future?

I'm worried it will negatively impact me getting into university/college (159)
44.41%
I'm worried that I’m not academically prepared for the next stage in my educational journey (40)
11.17%
I'm worried it will impact my future career (29)
8.1%
I'm worried that my grades will be seen as ‘lesser’ because I didn’t take exams (75)
20.95%
I don’t think that receiving these grades will impact my future (34)
9.5%
I think that receiving these grades will affect me in another way (let us know in the discussion!) (21)
5.87%

Watched Threads

View All
Latest
My Feed