The perimeter of triangle ABC

The national average for the math portion of the College Board’s Scholastic Aptitude Test

Alex73 [517]

Answer:

a) 0.1587

b) 0.023

c) 0.341

d) 0.818

Step-by-step explanation:

We are given the following information in the question:

Mean, μ = 515

Standard Deviation, σ = 100

We are given that the distribution of SAT score is a bell shaped distribution that is a normal distribution.

Formula:

$z_{score} = \displaystyle\frac{x-\mu}{\sigma}$

a) P(score greater than 615)

P(x > 615)

$P( x > 615) = P( z > \displaystyle\frac{615 - 515}{100}) = P(z > 1)$

$= 1 - P(z \leq 1)$

Calculation the value from standard normal z table, we have,

$P(x > 615) = 1 - 0.8413 = 0.1587 = 15.87\%$

b) b) P(score greater than 715)

$P(x > 715) = P(z > \displaystyle\frac{715-515}{100}) = P(z > 2)\\\\P( z > 2) = 1 - P(z \leq 2)$

Calculating the value from the standard normal table we have,

$1 - 0.977 = 0.023 = 2.3\%\\P( x > 715) = 2.3\%$

c) P(score between 415 and 515)

$P(415 \leq x \leq 515) = P(\displaystyle\frac{415 - 515}{100} \leq z \leq \displaystyle\frac{515-515}{100}) = P(-1 \leq z \leq 0)\\\\= P(z \leq 0) - P(z < -1)\\= 0.500 - 0.159 = 0.341 = 34.1\%$

$P(415 \leq x \leq 515) = 34.1\%$

d) P(score between 315 and 615)

$P(315 \leq x \leq 615) = P(\displaystyle\frac{315 - 515}{100} \leq z \leq \displaystyle\frac{615-515}{100}) = P(-2 \leq z \leq 1)\\\\= P(z \leq 1) - P(z < -2)\\= 0.841 - 0.023 = 0.818 = 81.8\%$

$P(315 \leq x \leq 615) = 81.8\%$

4 0

4 years ago

WILL MARK THE BRAINLIEST

Elis [28]

Answer:

Option D, 16/21

Step-by-step explanation:

Step 1: Add all of them together

5 + 7 + 9

21

Step 2: Figure out how much of the plants are medicinal

7 + 9

16

Step 3: Figure out the probability

16/21

Answer: Option D, 16/21

7 0

3 years ago

Type the correct answer in the box. Use numerals instead of words. If necessary, use / for the fraction bar.

Rama09 [41]

Answer:

27

Step-by-step explanation:

math

3 0

3 years ago

the volume of a gas varies inversely as the pressure upon it. if the volume of the gas is 160 cubic centimeters at a pressure of

marin [14]

It was stated in the problem that a given volume of a is inversely proportional with the pressure of the system. It means that the as the volume increases, the pressure would decrease and as the volume decreases, the pressure would increase. We would express it as:

V α 1/P

To change it to an equality, we introduce a proportionality constant, k. We do as follows:

V = k/P

So, to determine what is asked, we need to first calculate for the value of k.

V = k/P
At V = 160 m^3 P = 108 cmHg
160 = k / (108)
k = 17280

Thus, at P = 87 cmHg
V = 17280 / 87
V = 198.62 m^3

4 0

3 years ago

C. you will break even when the cost of your materials equals your income. how many bracelets must you sell to break even? you m

STALIN [3.7K]

Since this is part C, we're gonna need more information than that because we don't have your exact homework! Maybe reupload ? I would need the calculations for the cost of bracelets and how much were sold to see the break even point to be accurate!

6 0

3 years ago