All categories

3 years ago

The sum of a number $x$ and 4 equals 12.

Mathematics

1 answer:

djverab [1.8K]3 years ago

3 0

Answer:

The number is 8

Step-by-step explanation:

Lets say the number is x

1: Create equation

x+4=12

2: Subtract 4 from both sides

x+4-4=12-4

x+0=8

x=8

The number is 8

You might be interested in

1. A company produces batteries. On average, 85% of all batteries produced are good. Each battery is tested before being dispatc

pogonyaev

Answer:

A. 78%

B. 1.92%

Step-by-step explanation:

Given the information:

85% of all batteries produced are good
The inspector correctly classifies the battery 90%

A. What percentage of the batteries will be “classified as good”?

The percentage of batteries are not good is:

100% - 85% = 15% and of those 100-90 = 10% will be classified as good. Hence, we have:

= 0.85*0.9 + 0.15*0.1 = 0.78

= 78%

So 78% of the batteries will be “classified as good”

B. What is the probability that a battery is defective given that it was classified as good?

We will use the conditional probability formula in this situation:

$P(B|A) = \frac{P(A \cap B)}{P(A)}$ where:

P(A) is the probability of A happening. (A is classified as good) => P(A) = 78%

P(B|A) is the probability of event B happening, given that A happened. (B classified as detective)

$P(A \cap B)$ is the probability of both events happening => $P(A \cap B) = 0.15*0.1 = 0.015$ (5% of the batteries are not good. Of those, 100-90 = 10% will be classified as good)

We have:

$P(B|A) = \frac{P(A \cap B)}{P(A)}$ = $\frac{0.015}{0.78}$ = 0.0192 = 1.92%

Hence, 1.92% probability that a battery is defective given that it was classified as good

7 0

3 years ago

What is the sum of the series?

otez555 [7]

Okay, the number above the sigma(4) indicates what value you go to, and what's below the sigma tells you where to start, and the stuff on the right is the expression you're using.

So we start with 1 and go to 4, adding all the values in between.

(2(1))^2 + (2(2))^2 + (2(3))^2 + (2(4))^2

2^2 + 4^2 + 6^2 + 8^2

4 + 16 + 36 + 64

120

4 0

3 years ago

Please please please helppppppppp

notka56 [123]

Answer:

Step-by-step explanation:

She added 3x and -2x, getting 5x, instead of x. She needs to pay more attention to the positive/negative signs.

6 0

3 years ago

How do you compare two-way frequencies in a relative frequency table

Nikolay [14]

To avoid such problems when comparing the categorical variables in a two-way frequency table, we need to exam the table by separate categories (rows or columns). When a relative frequency is determined based upon a row or column, it is called a "conditional" relative frequency.
Two-way relative frequency tables show what percent of data points fit in each category. ...
For example, here's how we would make column relative frequencies:
Step 1: Find the totals for each column.
Step 2: Divide each cell count by its column total and convert to a percentage.

3 0

3 years ago

the table shows the highest of four students arrange the students in order from shortest to tallest Kim 56.03 + x + 56.3 + 56.14

saul85 [17]

56.03 56.14 56.3 57.1

6 0

3 years ago