Write the point-slope form of the equation of the line that passes through the point (-1, 5) and has a slope of -1.

* The standard deviation (a measure of variability or dispersion) describes the lowest and highest any individual penny weight can be. Subtracting 0.02g from the mean, you get the lowest penny weight in the group.

Step-by-step explanation:

Recall that a penny is a money unit. It is created/produced, just like any other commodity. As a matter of fact, almost all types of money or currency are manufactured; with different materials ranging from paper to solid metals.

A group of pennies made in a certain year are weighed. The variable of interest here is weight of a penny.

The mean weight of all selected pennies is approximately 2.5grams.

The standard deviation of this mean value is 0.02grams.

In this context,

* The mean (a measure of central tendency) weight value is the average of the weights of all pennies in the study.

* The standard deviation (a measure of variability or dispersion) describes the lowest and highest any individual penny weight can be. Subtracting 0.02g from the mean, you get the lowest penny weight in the group.

Likewise, adding 0.02g to the mean, you get the highest penny weight in the group.

Hence, the weight of each penny in this study, falls within

[2.48grams - 2.52grams]

4 0

3 years ago

Test scores of the student in a school are normally distributed mean 85 standard deviation 3 points. What's the probability that

Mrrafil [7]

Answer:

The probability that a random selected student score is greater than 76 is $\\ P(x>76) = 0.99865$ .

Step-by-step explanation:

The Normally distributed data are described by the normal distribution. This distribution is determined by two parameters, the population mean $\\ \mu$ and the population standard deviation $\\ \sigma$ .

To determine probabilities for the normal distribution, we can use the standard normal distribution, whose parameters' values are $\\ \mu = 0$ and $\\ \sigma = 1$ . However, we need to "transform" the raw score, in this case x = 76, to a z-score. To achieve this we use the next formula:

$\\ z = \frac{x - \mu}{\sigma}$ [1]

And for the latter, we have all the required information to obtain z. With this, we obtain a value that represent the distance from the population mean in standard deviations units.

<h3>The probability that a randomly selected student score is greater than 76</h3>

To obtain this probability, we can proceed as follows:

First: obtain the z-score for the raw score x = 76.

We know that:

$\\ \mu = 85$

$\\ \sigma = 3$

$\\ x = 76$

From equation [1], we have:

$\\ z = \frac{76 - 85}{3}$

Then

$\\ z = \frac{-9}{3}$

$\\ z = -3$

Second: Interpretation of the previous result.

In this case, the value is three (3) standard deviations below the population mean. In other words, the standard value for x = 76 is z = -3. So, we need to find P(x>76) or P(x>-3).

With this value of $\\ z = -3$ , we can obtain this probability consulting the cumulative standard normal distribution, available in any Statistics book or on the internet.

Third: Determination of the probability P(x>76) or P(x>-3).

Most of the time, the values for the cumulative standard normal distribution are for positive values of z. Fortunately, since the normal distributions are symmetrical, we can find the probability of a negative z having into account that (for this case):

$\\ P(z>-3) = 1 - P(z>3) = P(z$

Then

Consulting a cumulative standard normal table, we have that the cumulative probability for a value below than three (3) standard deviations is:

$\\ P(z$

Thus, "the probability that a random selected student score is greater than 76" for this case (that is, $\\ \mu = 85$ and $\\ \sigma = 3$ ) is $\\ P(x>76) = P(z>-3) = P(z$ .

As a conclusion, more than 99.865% of the values of this distribution are above (greater than) x = 76.

We can see below a graph showing this probability.

As a complement note, we can also say that:

$\\ P(z3)$

Which is the case for the probability below z = -3 [P(z<-3)], a very low probability (and a very small area at the left of the distribution).

5 0

3 years ago

write an equation in slope intercept form for the line that passes through the point, and is perpendicular to the line y=-1/3x+9

aleksklad [387]

Answer:

Step-by-step explanation:

y=-1/3x+9

This is written in the format y=mx+b, where m is the slope and b the y-intercept (the value of y when x=0).

Perpendicular lines have a slope that is the negative inverse of the slope of the reference line, in this case -(1/3). The new slope is 3. equation is:

y = 3x + b

To find b, enter the given point, (-6,-2) and solve for b:

y = 3x + b

-2 = 3(-6) + b

-2 = -18 + b

b = 16

The full equation is y=3x + 18

8 0

3 years ago