Monitors manufactured by TSI Electronics have life spans that have a normal distribution with a standard deviation of 1900 hours and a mean life span of 19,000 hours. If a monitor is selected at random, find the probability that the life span of the monitor will be more than 15,579 hours. Round your answer to four decimal places.

0.9641 = 96.41% probability that the life span of the monitor will be more than 15,579 hours.

Step-by-step explanation:

Problems of normally distributed samples are 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:

Find the probability that the life span of the monitor will be more than 15,579 hours.

This is 1 subtracted by the pvalue of Z when X = 15579. So

has a pvalue of 0.0359

1 - 0.0359 = 0.9641

0.9641 = 96.41% probability that the life span of the monitor will be more than 15,579 hours.

2. angles qrt and qst both measures 156 degrees.

step-by-step explanation:  

we have been given a diagram of a circle and we are told that measure of arc qvt is 156 degrees.  

we can see from our given diagram that angle qrt and angle qst subtends to arc qvt.

since we know that angles subtended by the same arc at the circumference are always equal.

by angle subtended by same arc theorem, measure of angle qrt and angle qst will be equal to the measure of arc qvt.

therefore, angles qrt and qst both measures 156 degrees and 2nd statement is the correct choice.

can you put the picture up?

step-by-step explanation: