What is the probability that a randomly selected light bulb will burn out in 1200 hours or less?
What is a probability?
To solve these problems using the above steps, first draw a picture of the normal distribution at hand.
Sample Question: Suppose that a contaminant in samples from a citys water supply has a mean of 500 ppm and a standard deviation of 100 ppm.The cumulative probability.90, since Bill has to outperform 90 of the boys.To transform a normal random variable (x) into an equivalent standard score (z use the following formula: z ( x - ) / where is the mean, and is the standard deviation.(If he had claimed to outperform only 80 of the boys, the cumulative probability would.80.) Therefore, we plug those numbers into the Normal Distribution Calculator and hit the Calculate button.For example, you could look at the distribution of fish lengths in a pond to determine how likely you are to catch a certain length of fish.And Problem 3 is looking for p (16 X 24).See: Normal distributions Word Problems.Because the entire probability for the Z- distribution equals 1, you know p (.00) 1 p (.00).9772.0228 (using the Z- table).It is a measure of the average distance of individual observations from the group mean.The distribution of fish lengths in a pond This figure shows a picture of X s distribution for fish lengths.The probability that X is equal to any single ip tools for windows value is 0 for any continuous random variable (like the normal).
Thats because continuous random variables consider probability as being area under the curve, and theres no area under a curve at one single point.