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3 years ago

Evaluate this expression (-7--9)*(8+2)

1 answer:

5 0

Before we get started, it is good to remember PEMDAS - the acronym that tells you the order to carry out equations.

P = parentheses
E = exponents
M = multiplication
D = division
A = addition
S = subtraction

Knowing this, we should start by doing the equations <em>within </em>each parentheses.

$(-7 - -9) *(8 + 2)$
$(2) *(10)$

So we did the addition and subtraction pieces within each group leaving us with the above equation. Now let's multiply:

$(2)*(10) = 20$

20 is the answer.

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How to factor 98x squared-50

Grace [21]

I believe this is the answer
$98 { x }^{2} - 50 = 2(49{x}^{2} - 25)$

good luck

7 0

3 years ago

Suppose 45% of the population has a college degree.

levacccp [35]

Using the normal distribution, there is a 0.2076 = 20.76% probability that the proportion of persons with a college degree will differ from the population proportion by greater than 3%.

<h3>Normal Probability Distribution</h3>

The z-score of a measure X of a normally distributed variable with mean $\mu$ and standard deviation $\sigma$ is given by:

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

The z-score measures how many standard deviations the measure is above or below the mean.

Looking at the z-score table, the p-value associated with this z-score is found, which is the percentile of X.

By the Central Limit Theorem, for a proportion p in a sample of size n, the sampling distribution of sample proportion is approximately normal with mean $\mu = p$ and standard deviation $s = \sqrt{\frac{p(1 - p)}{n}}$ , as long as $np \geq 10$ and $n(1 - p) \geq 10$ .

The proportion estimate and the sample size are given as follows:

p = 0.45, n = 437.

Hence the mean and the standard error are:

$\mu = p = 0.45$

$s = \sqrt{\frac{p(1 - p)}{n}} = \sqrt{\frac{0.45(0.55)}{437}} = 0.0238$

The probability that the proportion of persons with a college degree will differ from the population proportion by greater than 3% is <u>2 multiplied by the p-value of Z when X = 0.45 - 0.03 = 0.42</u>.

Hence:

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

By the Central Limit Theorem:

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

Z = (0.42 - 0.45)/0.0238

Z = -1.26

Z = -1.26 has a p-value of 0.1038.

2 x 0.1038 = 0.2076.

0.2076 = 20.76% probability that the proportion of persons with a college degree will differ from the population proportion by greater than 3%.

More can be learned about the normal distribution at brainly.com/question/28159597

#SPJ1

8 0

2 years ago

Simplify the expression (-6i)(-6i)

AURORKA [14]

Answer:

36i^2 i think that's right

8 0

3 years ago

What is the domain of the function y=sqrt x+6-7

harkovskaia [24]

Answer:

$x \geqslant 1$

Step-by-step explanation:

$\sqrt{x + 6 - 7} = \sqrt{x - 1} \\ \\ x - 1 \geqslant 0 \\ x \geqslant 1$

8 0

3 years ago

I am about to take a 2020-2021 math grade 5 unit 2 part 2 assessment what should i do?

shutvik [7]

Answer:

You should study for about 30-60 minutes and make sure your somewhere quite so you can focus. While you take your assessment you want water, and maybe some gum.

8 0

3 years ago