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3 years ago

Solve 3/x + 8/y = -1 ; 1/x - 2/y = 2

Mathematics

1 answer:

Gelneren [198K]3 years ago

3 0

Answer:

x=-3y/8+y; y not equal to -8

x=y/2(1+y); y not equal to -1

Step-by-step explanation:

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Everyone wants to watch football games on Thanksgiving. There are 3 games on in afternoon and 3 on at night. How many different

Vikki [24]

Answer:

Step-by-step explanation:

At afternoon there are 3 games, lets call them A1, A2, and A3. These are simultaneous, which means you can ONLY watch one of them.

At night there are other three, lets call them N1, N2 and N3. Which again, are simultaneous, so you need to chose only one.

So, you can, at most, watch 2 games: one in the afternoon (extracted from the set {A1, A2, A3}) and one at night (extracted from the set {N1, N2, N3}).

So, here what you need is ALL the possible combinations between afternoon and games. As thee choices are independent, this is, the game chosen at afternoon has no effect on the night decision, we can just multiply the number of options in every set: 3*3 = 9. So there are 9 different combinations, which are:

A1 N1, A1 N2, A1 N3, A2 N1, A2 N2, A2 N3, A3 N1, A3 N2, A3 N3.

Here I supposed you watch a game in both, night and afternoon. If you can choose to NOT watch any game, the sets will have 4 elements but the reasoning is equal.

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3 years ago

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Answer:

Step-by-step explanation:

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3 years ago

The following data shows the scores Gina obtained on 12 IQ tests: 93, 83, 74, 74, 83, 92, 93, 94, 90, 87, 83, 86 The box plot be

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Maxium value equal to 99 i think but idk for sure

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4 years ago

Read 2 more answers

Thompson and Thompson is a steel bolts manufacturing company. Their current steel bolts have a mean diameter of 144 millimeters,

kkurt [141]

Answer:

0.0524 = 5.24% probability that the sample mean would differ from the population mean by more than 2 millimeters.

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 z-score 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 p-value, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem establishes 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 $s = \frac{\sigma}{\sqrt{n}}$ .

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

Mean diameter of 144 millimeters, and a variance of 49.

This means that $\mu = 144, \sigma = \sqrt{49} = 7$

Sample of 46:

This means that $n = 46, s = \frac{7}{\sqrt{46}}$

Wat is the probability that the sample mean would differ from the population mean by more than 2 millimeters?

Above 144 + 2 = 146 or below 144 - 2 = 142. Since the normal distribution is symmetric, these probabilities are equal, which means that we find one of them and multiply by two.

Probability the sample mean is below 142:

p-value of Z when X = 142, so:

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

By the Central Limit Theorem

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