The pH measurements of water specimens from various locations along a given river basin are Normally distributed with mean 8 and standard deviation 0.3. You take water specimens from 4 randomly selected locations on this river basin.
1. What is the probability that the mean pH measurement of these 4 specimens is greater than 8.2?
A. 0.2546
B. 0.7454
C. 0.0918
D. 0.9082

C) 0.0918

Step-by-step explanation:

Let be the mean pH measurement of these 4 specimens, we know that this random variable is normally distributed with mean 8 and standard deviation , this because we have a sample size n = 4. We are looking for , the z-score related to 8.2 is (8.2-8)/0.15=1.3333, therefore, .

pentagon

step-by-step explanation:

the coordinates   a(5, -2), b(3,-1),c(-4,-4) d(-3,8) and e(-1,4) forms the vertices of the polygon when they are connected in order.

in order to classify that which polygon is it with the given coordinates, first count the number of vertices and then count the number of sides it can make with these vertices.

since, the given coordinates have five vertices, therefore, it will make five sides. moreover, pentagon is regular in nature therefore it will be convex.

now, a polygon with five sides is known as pentagon, therefore, the given polygon is the pentagon.

option a is correct.

step-by-step explanation:

scale factor: it is used to find proportional measurements.

proportions means having the same ratio.

scale factor is the ratio of the model measurement to the actual measurement in a simplest form.

or we can say that the ratio of any two corresponding lengths in two similar geometric figures

if the scale factor is more than 1, then it is an enlargement,

if the scale factor less than 1, then it is a reduction.

given the two geometric figure:

by definition of proportions, we have