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3 years ago

Define theoretical and experimental probability and how we can relate the two.

1 answer:

6 0

Theoretical probability is the term used to describe what we expect to happen based on math theory, whereas experimental probability refers to what actually happens when the actual situation is tried out as an experiment.

We can relate the two types of probability by comparing their values - the values should be relatively close. In most experiments, they will not be equal, but they should be relatively close; if not, it may be that the experiment was conducted improperly or more trials need to be completed.

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Assume that a randomly selected subject is given a bone density test. Those test scores are normally distributed with a mean of

jarptica [38.1K]

Answer:

The "probability that a given score is less than negative 0.84" is $\\ P(z$ .

Step-by-step explanation:

From the question, we have:

The random variable is normally distributed according to a standard normal distribution, that is, a normal distribution with $\\ \mu = 0$ and $\\ \sigma = 1$ .
We are provided with a z-score of -0.84 or $\\ z = -0.84$ .

Preliminaries

A z-score is a standardized value, i.e., one that we can obtain using the next formula:

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

Where

x is the raw value coming from a normal distribution that we want to standardize.
And we already know that $\\ \mu$ and $\\ \sigma$ are the mean and the standard deviation, respectively, of the normal distribution.

A z-score represents the distance from $\\ \mu$ in standard deviations units. When the value for z is negative, it "tells us" that the raw score is below $\\ \mu$ . Conversely, when the z-score is positive, the standardized raw score, x, is above the mean, $\\ \mu$ .

Solving the question

We already know that $\\ z = -0.84$ or that the standardized value for a raw score, x, is below $\\ \mu$ in 0.84 standard deviations.

The values for probabilities of the standard normal distribution are tabulated in the standard normal table, which is available in Statistics books or on the Internet and is generally in cumulative probabilities from negative infinity, - $\\ \infty$ , to the z-score of interest.

Well, to solve the question, we need to consult the standard normal table for $\\ z = -0.84$ . For this:

Find the cumulative standard normal table.
In the first column of the table, use -0.8 as an entry.
Then, using the first row of the table, find -0.04 (which determines the second decimal place for the z-score.)
The intersection of these two numbers "gives us" the cumulative probability for z or $\\ P(z$ .

Therefore, we obtain $\\ P(z$ for this z-score, or a slightly more than 20% (20.045%) for the "probability that a given score is less than negative 0.84".

This represent the area under the standard normal distribution, $\\ N(0,1)$ , at the left of z = -0.84.

To "draw a sketch of the region", we need to draw a normal distribution (symmetrical bell-shaped distribution), with mean that equals 0 at the middle of the distribution, $\\ \mu = 0$ , and a standard deviation that equals 1, $\\ \sigma = 1$ .

Then, divide the abscissas axis (horizontal axis) into equal parts of one standard deviation from the mean to the left (negative z-scores), and from the mean to the right (positive z-scores).

Find the place where z = -0.84 (i.e, below the mean and near to negative one standard deviation, $\\ -\sigma$ , from it). All the area to the left of this value must be shaded because it represents $\\ P(z$ and that is it.

The below graph shows the shaded area (in blue) for $\\ P(z$ for $\\ N(0,1)$ .

7 0

3 years ago

Boyd’s dartboard is octagonal. Each side measures 9 in. He drew a copy of the board that was smaller by a scale factor 0.25.

Basile [38]

The question is about the side length of a copy of the dartboard. We know that the original dartboard has sides that measure 9 inches. We also have the scale factor 0.25. The ratio of the corresponding sides is called the scale factor. If we have the scale factor 0.25 it means that for 1 unit of the original figure there are 0.25 units of length of a copy. Therefore: x = 9 * 0.25; x = 2.25 in. Answer: The side length of the dartboard Boyd drew is 2.25 inches.

5 0

3 years ago

H=(-5) answer needed now!!!!

wariber [46]

Answer:

-2

Step-by-step explanation:

h(-5) represents the y value when x is -5.

7 0

3 years ago

What is the y-intercept of the function f(x) = _2/9×+1/3

Leokris [45]

Answer:The y intercept is (0.0.333)

Step-by-step explanation:

5 0

3 years ago

if trapezoid ABCD was reflected over the y-axis, reflected over the x-axis, and rotated 180°, where would point A’lie

maria [59]

Answer:

Answer: (second option) (-4,1)

Step-by-step explanation:

Transformations of Points and Shapes

The image shows a trapezoid ABCD where point A has coordinates (-4,1).

The following transformations are performed:

Reflection over the y-axis: If a point (x,y) is reflected over the y-axis, it becomes (-x,y). Thus point A becomes A'=(4,1)

Reflection over the x-axis: If a point (x,y) is reflected over the x-axis, it becomes (x,-y). Thus point A' becomes A''=(4,-1)

Rotation 180°: If a point (x,y) is rotated 180°, it becomes (-x,-y). Thus point A'' becomes A'''=(-4,1)

Answer: (second option) (-4,1)

5 0

3 years ago