can someone help me solve the follwoing statistics question with explanations pl
ID: 3043109 • Letter: C
Question
can someone help me solve the follwoing statistics question with explanations please, i really want to know how each part was solved in detail.
I) A random sample of 1000 alkaline AA batteries (of various brands) were tested and the following information was recorded for their lifetimes: The mean lifetime was 7.5 hours and the standard deviation was 1.5 hours. The median lifetime was 7 hours; the 90th percentile of the lifetimes was 10 hours while the 10th percentile was 5.75 hours.
Answer (a) – (e) based on the above information
a) What percentage of batteries lasted longer than 10 hours?
b) What percentage of the batteries lasted longer than 7 hours?
c) Can we say anything about the percentage of the batteries that lasted longer than 7.5 hours? If so, what?
d) What percentage of lifetimes were in the interval (5.75, 10)? How about in the interval (5.75, 7)?
e) How would you describe the shape of the distribution of the lifetimes?
pleas help
Explanation / Answer
a) as 10 hours is at 90 th percentile ; therfore (100-90)=10 percentage of batteries lasted longer than 10 hours
b)as
median is at 7 hours means 50 percentage of the batteries lasted longer than 7 hours
c)
as mean is greater than median and not equal therefore distribution is not symmetric and right skewed
only thing we can say is that percentage of the batteries that lasted longer than 7.5 hours is less than 50%.
d)percentage of lifetimes were in the interval (5.75, 10) =90-10=80%
about in the interval (5.75, 7) =50-10 =40%
e) the shape of the distribution is right skewed as mean is greater than median.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.