# Standard Deviation Questions

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## Latest Questions

### A batch of 5000 electric lamps has been a mean of 1000 hours and a standard deviation of 75 hours.

Assuming a normal distribution a) how many lamps will fall before 900 hours b) how many lamps will fall between 950 and 1025 c)what is proportional ...

### Construct a 99% confidence interval estimate of the difference μs−μf?

Randomly selected 15 student cars have ages with a mean of 8 years and a standard deviation of 3.4 years, while randomly selected 28 faculty cars ...

## Popular Questions

### A batch of 5000 electric lamps has a mean life of 1000 hours and a standard deviation of 75...

... hours. Assume a normal distribution. i) How many lamps will fail before ...

### Hello, I'm really bad in STAT and would really appreciate if someone simplifies the answer for me in

... a few steps? Q#1) suppose that a normal distribution has a ...

### I have a mean of 7.15 after I added up all my numbers and then divided by the amount of numbers. Now

... for standard deviation I subtract each sample from the mean, ...

### Why are they the same?

Compare the formula values to the Descriptive Statistics table values for mean, median, mode, variance, and standard deviation (In my statistics ...