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3 years ago

PLS HELP ME ASAP WITH THIS! (LOTS OF POINTS!) (show work OR explain)

Mathematics

1 answer:

riadik2000 [5.3K]3 years ago

7 0

So they tell you to let x represent the cost of Deandra's sofa. So since Selena's sofa costs 30 dollars LESS than HALF the cost of Deandra's, we know we have to divide by 2 and subtract 30.
The equation would be x/2-30. (B)

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How many times were you able to transfer any contents of the cone into the cylinder? What comparison can you make between the vo

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I do not know the last question but I know the first it is4 time I hope I am right

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3 years ago

24% of 289 estimated using<br> a rate per 100

zaharov [31]

Answer:

The answer would be 40!

Step-by-step explanation:

Estimating ~ rounding

I would round 24% (20%), and 289 (300).

using the formula:

$is/of \\$ = %/100,

I'm looking for "IS"

I multiply 20 (just 20, no percent) by 200 = 4000.

Then I divide by 100 to get the "IS".

That's how I got my answer!

Hope this helps!

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3 years ago

-3/7 plus (-3/4) reduce to simplest form

alina1380 [7]

Exact form
-3/2

Decimal form
-1.5

Mixed number form
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3 years ago

Read 2 more answers

the measure of two complimentary angles is in the ratio 1:9. what are the degree measures of the two angles

marusya05 [52]

$x+9x=90\\
10x=90\\
x=9\\
9x=9\cdot9=81$

9 and 81.

4 0

3 years ago

The scores of students on the ACT college entrance exam in a recent year had the normal distribution with mean  =18.6 and stand

Maurinko [17]

Answer:

a) 33% probability that a single student randomly chosen from all those taking the test scores 21 or higher.

b) 0.39% probability that the mean score for 76 students randomly selected from all who took the test nationally is 20.4 or higher

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal probability distribution:

Problems of normally distributed samples are solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

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

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

Central limit theorem:

The Central Limit Theorem estabilishes that, for a random variable X, with mean $\mu$ and standard deviation $\sigma$ , the sample means with size n of at least 30 can be approximated to a normal distribution with mean $\mu$ and standard deviation $s = \frac{\sigma}{\sqrt{n}}$

In this problem, we have that:

$\mu = 18.6, \sigma = 5.9$

a) What is the probability that a single student randomly chosen from all those taking the test scores 21 or higher?

This is 1 subtracted by the pvalue of Z when X = 21. So

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

$Z = \frac{21 - 18.6}{5.4}$

$Z = 0.44$

$Z = 0.44$ has a pvalue of 0.67

1 - 0.67 = 0.33

33% probability that a single student randomly chosen from all those taking the test scores 21 or higher.

b) The average score of the 76 students at Northside High who took the test was x =20.4. What is the probability that the mean score for 76 students randomly selected from all who took the test nationally is 20.4 or higher?

Now we have $n = 76, s = \frac{5.9}{\sqrt{76}} = 0.6768$