Water permeability of concrete can be measured by letting water flow across the surface and determining the amount lost (in inches per hour). suppose that the permeability index x for a randomly selected concrete specimen of a particular type is normally distributed with mean value 1000 and standard deviation 150. how likely is it that a single randomly selected specimen will have a permeability index between 550 and 1300?

97.59% probability that a single randomly selected specimen will have a permeability index between 550 and 1300.

Step-by-step explanation:

Problems of normally distributed samples can be solved using the z-score formula.

In a set with mean and standard deviation , the zscore of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

In this problem, we have that:

.

How likely is it that a single randomly selected specimen will have a permeability index between 550 and 1300?

This is the pvalue of Z when X = 1300 subtracted by the pvalue of Z when X = 550.

Z = 1300

has a pvalue of 0.9772

Z = 550

has a pvalue of 0.0013

So there is a 0.9772 - 0.0013 = 0.9759 = 97.59% probability that a single randomly selected specimen will have a permeability index between 550 and 1300.

0.32

step-by-step explanation:

2.24/7

answer: yard ramps with a level off platform are typically 36 feet long. truck, rather than at an angle, enabling access to those pallets at the very back of the truck. if you are using your yard ramp to convert a loading dock into a drive-in door, we even at 60 inches (5 feet) high and a 30 foot ramp, the slope of the ramp will be less

step-by-step explanation: