Stats help
Could anyone do this stats question on Normal Distribution and tell me what they got for mean and SD? I've done it but my answers seem really off. Thanks in advance. 
Assume that the lifetime of a certain type of light bulb can be modelled by the Normal
distribution. It is found that 6% of bulbs last for more than 1100 hours and 14% for less
than 970 hours.
What is the mean lifetime of a light bulb?
What is the standard deviation of the lifetime of a light bulb?
Assume that the lifetime of a certain type of light bulb can be modelled by the Normal
distribution. It is found that 6% of bulbs last for more than 1100 hours and 14% for less
than 970 hours.
What is the mean lifetime of a light bulb?
What is the standard deviation of the lifetime of a light bulb?
Original post by SS__
Could anyone do this stats question on Normal Distribution and tell me what they got for mean and SD? I've done it but my answers seem really off. Thanks in advance.
Assume that the lifetime of a certain type of light bulb can be modelled by the Normal
distribution. It is found that 6% of bulbs last for more than 1100 hours and 14% for less
than 970 hours.
What is the mean lifetime of a light bulb?
What is the standard deviation of the lifetime of a light bulb?
Assume that the lifetime of a certain type of light bulb can be modelled by the Normal
distribution. It is found that 6% of bulbs last for more than 1100 hours and 14% for less
than 970 hours.
What is the mean lifetime of a light bulb?
What is the standard deviation of the lifetime of a light bulb?
Post your answers and we can check
Original post by Notnek
Post your answers and we can check
Ah probz shoulda done that....my bad. The others got the same answer so it’s fine I guess.
Original post by the bear
µ = 1023, σ = 49.3
Thank you, ended with that too
Original post by SS__
Thank you, ended with that too
i got it from here:
https://uk.answers.yahoo.com/question/index?qid=20131216093506AAM38FA
the first answers look much better than the second ones
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