Which measure correctly completes the statement 2,231.5 milligrams =? grams

Simplify 2a+2−3a−5+a−4+7a.

zhuklara [117]

Answer:

7a-7

Step-by-step explanation:

2a+2−3a−5+a−4+7a.

Combine like terms

2a-3a+a+7a+2-5-4

7a-7

3 0

3 years ago

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Which number is greatest? 2.89 times 10 Superscript negative 8 1.997 times 10 Superscript 2 8.9 times 10 Superscript negative 6

love history [14]

<h3> The greatest number is $1.997 \times 10^2$ </h3>

Solution:

Given that the numbers are:

$2.89 \times 10^{-8}\\\\1.997 \times 10^2\\\\8.9 \times 10^{-6}\\\\5 \times 10^{-6}$

We have to find the number that is greatest

Convert the numbers to decimal

$2.89 \times 10^{-8} = 2.89 \times \frac{1}{10^8} =0.0000000289$

$1.997 \times 10^2 = 199.7$

$8.9\times 10^{-6}=8.9\times \frac{1}{10^6}=0.0000089$

$5\times 10^{-6}=5\times \frac{1}{10^6}=0.000005$

We can clearly see that, 199.7 is greatest number

Thus the greatest number is $1.997 \times 10^2$

3 0

4 years ago

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PLZ HELP ASAP!!!!!!!

Alexxx [7]

Answer:

angle 1 and angle 2 are supplementary angles

Step-by-step explanation:

When the base of the angles forms a straight line, the sum of the angles is 180°. That's the definition of supplementary angles.

Complementary angles form a right angle. The sum of complementary angles is 90°

A slightly silly way to remember Complementary angles: The two angles look at each other and compliment each other saying, "You look all right to me!"

"Yes, we are so right together!"

:)

6 0

3 years ago

An environmental group conducted a study to determine whether crows in a certain region were ingesting food containing unhealthy

nydimaria [60]

Part A

Given info:

xbar = sample mean = 4.90 ppm
s = sample standard deviation = 1.12 ppm
n = 23 = sample size

Because n > 30 is not true, and we don't know the population standard deviation (sigma), this means we must use a T distribution.

The degrees of freedom here are n-1 = 23-1 = 22.

At 90% confidence and the degrees of freedom mentioned, the t critical value is roughly t = 1.717

Use a T distribution table or calculator to determine this. If you don't have a calculator for the task, then you can search out "inverse T calculator" and there are tons of free options to pick from.

The margin of error E is

E = t*s/sqrt(n)

E = 1.717*1.12/sqrt(23)

E = 0.400982

This is approximate and accurate to 6 decimal places.

The confidence interval is going to be xbar plus or minus that E value

L = lower bound = xbar - E = 4.90 - 0.400982 = 4.499018 = 4.50

U = upper bound = xbar + E = 4.90 + 0.400982 = 5.300982 = 5.30

The confidence interval in the format of (L, U) is (4.50, 5.30)

You could also express it as the format L < mu < U and it would be 4.50 < mu < 5.30; however, I'll stick to the first method.

<h3>Answer: (4.50, 5.30)</h3>

=====================================================

Part B

Since we know sigma = 2.6 is the population standard deviation, we can use a Z distribution now.

At 90% confidence, the z critical value is roughly 1.645; use a table or calculator to determine this.

$n = \left(\frac{z*\sigma}{E}\right)^2\\\\n \approx \left(\frac{1.645*2.6}{0.03}\right)^2\\\\n \approx 20325.254444 \\\\$

Round this up to the nearest integer to get 20326. For min sample size problems, always round up.

<h3>Answer: 20326</h3>

6 0

2 years ago

Solve for x: 3(x + 1) = −2(x − 1) − 4 1 −1 −5 −25

LekaFEV [45]

Answer:

x = - 1

Step-by-step explanation:

3(x + 1) = - 2(x - 1) - 4 ← distribute parenthesis on both sides

3x + 3 = - 2x + 2 - 4

3x + 3 = - 2x - 2 ( add 2x to both sides )

5x + 3 = - 2 ( subtract 3 from both sides )

5x = - 5 ( divide both sides by 5 )

x = - 1

7 0

2 years ago