Help me get the area of triangles and parallelograms

Estimating percents 19% of 72<br><br> Pleas explain how because I don’t understand this

jeka57 [31]

Answer:

13.68

Step-by-step explanation:

72 * 0.19 = 13.68

19% can be converted to 19/100 or .19 to change out of a percentage. .19 is the multiplied by 72 to find 19% of 72.

For example

a fourth of something is the same as 25%.

if you want to find 1/4 of 8 you would multiply 8 by 1/4.

It is a similar concept with percentages.

5 0

1 year ago

A set of test scores is normally distributed with a mean of 130 and a standard deviation of 30 What score is necessary to reach

nlexa [21]

Answer:

A score of 150.25 is necessary to reach the 75th percentile.

Step-by-step explanation:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

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.

A set of test scores is normally distributed with a mean of 130 and a standard deviation of 30.

This means that $\mu = 130, \sigma = 30$

What score is necessary to reach the 75th percentile?

This is X when Z has a pvalue of 0.75, so X when Z = 0.675.

$Z = \frac{X - \mu}{\sigma}$

$0.675 = \frac{X - 130}{30}$

$X - 130 = 0.675*30$

$X = 150.25$

A score of 150.25 is necessary to reach the 75th percentile.

7 0

3 years ago

Find the rectangular coordinates of the point (squareroot3, pi/6)

svet-max [94.6K]

Answer:

The rectangular coordinates of the point are (3/2 , √3/2)

Step-by-step explanation:

* Lets study how to change from polar form to rectangular coordinates

- To convert from polar form (r , Ф) to rectangular coordinates (x , y)

use these rules

# x = r cos Ф

# y = r sin Ф

* Now lets solve the problem

∵ The point in the rectangular coordinates is (√3 , π/6)

∴ r = √3 and Ф = π/6

- Lets find the x-coordinates

∵ x = r cos Ф

∵ r = √3

∵ Ф = π/6

∴ x = √3 cos π/6

∵ cos π/6 = √3/2

∴ x = √3 (√3/2) = 3/2

* The x-coordinate of the point is 3/2

- Lets find the y-coordinates

∵ y = r sin Ф

∵ r = √3

∵ Ф = π/6

∴ y = √3 sin π/6

∵ sin π/6 = 1/2

∴ y = √3 (1/2) = √3/2

* The y-coordinate of the point is √3/2

∴ The rectangular coordinates of the point are (3/2 , √3/2)

6 0

3 years ago

Gavin made a wooden planter in the shape of a cube. He measured the inside of the planter and found that each side is 38.75 cm l

notka56 [123]

Answer:

3/5

Step-by-step explanation:

7 0

3 years ago

Read 2 more answers

Consider the function y = -2-3cos (x+pi). What effect does the -2 have on the basic graph

Elenna [48]

ANSWER

-2 shift the graph of the basic function down by 2 units.

EXPLANATION

The given cosine function is:

$y = - 2 - 3 \cos(x + \pi)$

This equation can be rewritten as:

$y = - 3 \cos(x + \pi) + - 2$

We compare this to

$y = a \cos(bx + c) + d$

The effect d has on the graph is that, it shifts the graph up by d units.

If d is negative the graph shifts down by d units.

Since d=-2, the graph will shift down by 2 units.

5 0

3 years ago