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2 years ago

Simplify 2x - x + 4x

Mathematics

1 answer:

melamori03 [73]2 years ago

5 0

The answer is 5x (combine like terms) also remember x=1 so it actually 2x - 1x +4x, hope that helps :)

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2. In one year, there were a total of 13,332 kidney transplants

Sloan [31]

Answer:

i think it is 37

Step-by-step explanation:

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3 years ago

Elijah's uncle gave him $300 to spend on baseball equipment. He bought a pair of cleats for $69.99, two baseball jerseys for $32

dalvyx [7]

9514 1404 393

Answer:

$70

Step-by-step explanation:

The amount Elijah has remaining is ...

$300 -(70 +2×33 +80 +2×7) = $300 -(70 +80 +2(33 +7)) = $300 -230 = $70

To the nearest dollar, Elijah has $70 left.

_____

Each amount is within a penny of the nearest dollar, so we can simply use the nearest dollar amounts for the prices. In order for the answer to be different, Elijah would have to purchase 50 or more items with this pricing (something.99).

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3 years ago

25 is 8% of what numbet

Lelu [443]

Answer:

312.5%

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Step-by-step explanation:

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2 years ago

The amounts of electricity bills for all households in a city have a skewed probability distribution with a mean of $139 and a

ZanzabumX [31]

Answer:

P (within $6 of 4) = 0.9164

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 normal distributions can be 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 normally distributed random variable X, with mean $\mu$ and standard deviation $\sigma$ , the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean $\mu$ and standard deviation $s = \frac{\sigma}{\sqrt{n}}$ .

Mean of $139 and a standard deviation of $30.

This means that $\mu = 139, \sigma = 30$

Random sample of 75 households

This means that $n = 75, s = \frac{30}{\sqrt{75}} = 3.464$

75 > 30, which means that the sampling distribution is approximately normal.

Find the probability that the mean amount of electric bills for a random sample of 75 households selected from this city will be within $6 of the population mean.

This is the pvalue of Z when X = 139 + 6 = 145 subtracted by the pvalue of Z when X = 139 - 6 = 133.

X = 145

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

By the Central Limit Theorem

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