Use a property of equality to solve this equation 4.5x=18

All the fourth-graders in a certain elementary school took a standardized test. A total of 85% of the students were found to be

Aneli [31]

Answer:

There is a 2% probability that the student is proficient in neither reading nor mathematics.

Step-by-step explanation:

We solve this problem building the Venn's diagram of these probabilities.

I am going to say that:

A is the probability that a student is proficient in reading

B is the probability that a student is proficient in mathematics.

C is the probability that a student is proficient in neither reading nor mathematics.

We have that:

$A = a + (A \cap B)$

In which a is the probability that a student is proficient in reading but not mathematics and $A \cap B$ is the probability that a student is proficient in both reading and mathematics.

By the same logic, we have that:

$B = b + (A \cap B)$

Either a student in proficient in at least one of reading or mathematics, or a student is proficient in neither of those. The sum of the probabilities of these events is decimal 1. So

$(A \cup B) + C = 1$

In which

$(A \cup B) = a + b + (A \cap B)$

65% were found to be proficient in both reading and mathematics.

This means that $A \cap B = 0.65$

78% were found to be proficient in mathematics

This means that $B = 0.78$

$B = b + (A \cap B)$

$0.78 = b + 0.65$

$b = 0.13$

85% of the students were found to be proficient in reading

This means that $A = 0.85$

$A = a + (A \cap B)$

$0.85 = a + 0.65$

$a = 0.20$

Proficient in at least one:

$(A \cup B) = a + b + (A \cap B) = 0.20 + 0.13 + 0.65 = 0.98$

What is the probability that the student is proficient in neither reading nor mathematics?

$(A \cup B) + C = 1$

$C = 1 - (A \cup B) = 1 - 0.98 = 0.02$

There is a 2% probability that the student is proficient in neither reading nor mathematics.

6 0

2 years ago

One of the legs of a right triangle measures 9 cm and the other leg measures 11 cm.

ikadub [295]

Answer:

$\boxed {\boxed {\sf 14.2 \ cm}}$

Step-by-step explanation:

Since this is a right triangle, we can use the Pythagorean Theorem to solve for the sides.

$a^2+b^2=c^2$

where a and b are the legs and c is the hypotenuse. In this triangle, we know the legs are 9 centimeters and 11 centimeters, or:

a= 9 cm
b= 11 cm

Substitute these values into the formula.

$(9 \ cm)^{2} +(11 \ cm)^{2} =c^{2}$

Solve the exponents.

(9 cm)²= 9 cm*9 cm=81 cm²

$81 \ cm^{2} +(11 \ cm)^{2} =c^{2}$

(11 cm)²= 11 cm*11 cm= 121 cm²

$81 \ cm^{2} +121 cm^{2} =c^{2}$

Add the values on the left side.

$202 \ cm^{2} =c^{2}$

Since we are solving for c, we must isolate the variable. It is being squared and the inverse of a square is the square root. Take the square root of both sides.

$\sqrt {202 \ cm^{2} }=\sqrt{c^{2} }$

$\sqrt {202 \ cm^{2} }=c$

$14.2126704036 \ cm =c$

We are told to round to the nearest tenth.

14.2126704036

The 1 in the hundredth place tells us to leave the 2 in the tenth place.

$14.2 \ cm= c$

The hypotenuse is equal to 14.2 centimeters.

3 0

2 years ago

I want to know the simple way to add fractions like I have a problem with getting the answer to 1/6+1/8=

Jobisdone [24]

You find the lowest common denominator of both fractions, which in this case is 24.
1/6 is equivalent to 4/24 and 1/8 is equivalent to 3/24.
4/24 + 3/24 = 7/24

4 0

2 years ago

Read 2 more answers

I need help with these two questions can some explain it to me how to do these two question

GrogVix [38]

the numbers inside the () are first number is x second number is y so it is (x,y)

so for y<x the second number needs to be smaller than the first number

so right away (3,3) is not the answer

and then y also has to be greater then 2x-3

so replace x with the fist numbers and see what you get.

(2x2)-3 = 4-3 = -1 since -1 is not greater than -1 the second answer (2,-1) is not right

3rd one (-1,-2) 2(-1)-3 = -2-3=-5

so -2 is greater than -5 and -2 is less than -1 so the 3rd one is the answer

6 0

3 years ago

I need a answer plzzzz

Brilliant_brown [7]

Answer:

it`s acute because the angle is less than 90 degrees

8 0

2 years ago