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3 years ago

HELP ME PLSSS I kinda know what to do but at the same time, I'm so lost right now. help

Mathematics

1 answer:

Roman55 [17]3 years ago

7 0

Answer:

THEY messed you upon this one and I don't see if you have to write or not!

More details please and thank you!

Step-by-step explanation:

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Can a polygon have four sides and three angles

ollegr [7]

No a polygon only has 3 sides and 3 angles.

5 0

3 years ago

A metalworker has a metal alloy that is 15% copper and another alloy that is 60% copper. How many kilograms of each alloy shou

coldgirl [10]

18 kg of 15% copper and 72 kg of 60% copper should be combined by the metalworker to create 90 kg of 51% copper alloy.

<u>Step-by-step explanation:</u>

Let x = kg of 15% copper alloy

Let y = kg of 60% copper alloy

Since we need to create 90 kg of alloy we know:

x + y = 90

51% of 90 kg = 45.9 kg of copper

So we're interested in creating 45.9 kg of copper

We need some amount of 15% copper and some amount of 60% copper to create 45.9 kg of copper:

0.15x + 0.60y = 45.9

but

x + y = 90

x= 90 - y

substituting that value in for x

0.15(90 - y) + 0.60y = 45.9

13.5 - 0.15y + 0.60y = 45.9

0.45y = 32.4

y = 72

Substituting this y value to solve for x gives:

x + y = 90

x= 90-72

x=18

Therefore, in order to create 90kg of 51% alloy, we'd need 18 kg of 15% copper and 72 kg of 60% copper.

6 0

3 years ago

The head of the Westlane Cultural Center wants to get a sense of how quickly pledges from donors arrive at the center. It takes

Rzqust [24]

Answer:

95.64% probability that pledges are received within 40 days

Step-by-step explanation:

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.

In this problem, we have that:

$\mu = 28, \sigma = 7$