Answer:
13.5
Step-by-step explanation:
12/4=3
9/3=3
4.5x3=13.5
So you multiply 2 1/3times 1 1/2 and you get 3 and 1/6
Using the normal distribution, it is found that there is a 0.2776 = 27.76% probability that the life span of the monitor will be more than 20,179 hours.
<h3>Normal Probability Distribution</h3>
The z-score of a measure X of a normally distributed variable with mean
and standard deviation
is given by:

- The z-score measures how many standard deviations the measure is above or below the mean.
- Looking at the z-score table, the p-value associated with this z-score is found, which is the percentile of X.
The mean and the standard deviation are given, respectively, by:

The probability that the life span of the monitor will be more than 20,179 hours is <u>one subtracted by the p-value of Z when X = 20179</u>, hence:


Z = 0.59.
Z = 0.59 has a p-value of 0.7224.
1 - 0.7224 = 0.2776.
0.2776 = 27.76% probability that the life span of the monitor will be more than 20,179 hours.
More can be learned about the normal distribution at brainly.com/question/24663213
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In order to use the elimination method, we have to multiply the equation by some number, so that one of the variable has the same coefficient.
For example, multiplying the first equation by 3 and the second by 2 gives the following, equivalent system:

Now, we can subtract the two equations, and we will cancel (eliminate) the x variable:

Now that y is known, plug it into one of the equations: for example, if we use the first one we get

The ground, the building, and the ladder form a right triangle, in which
the leaning ladder is the hypotenuse.
For the angle between the ladder and the ground, the 4-ft along the ground
is the side adjacent to the angle, and the 7-ft ladder is the hypotenuse.
(adjacent side) / (hypotenuse) = cosine of the angle.
Cosine(a) = 4/7 = 0.57143... (rounded)
Angle 'a' = <em>55.15 degrees</em> (rounded)