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3 years ago

Suppose y varies directly as x and y=21 when x 3 find x when y=42

Mathematics

1 answer:

irga5000 [103]3 years ago

7 0

<span> 35
y=kx, where k is a constant
substitute in y=21 and x=3, you will get k=7
y=7(5)
y= 35 </span>

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5x4 - 7x3 + x + 2 <br> terms

Tomtit [17]

Answer:

It is already the farthest that can be

Step-by-step explanation:

5x4 - 7x3 + x + 2

5x^2 - 7x^2 + 1x + 2

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3 years ago

Suppose that the die is rolled twice, rather than once. find the probability of rolling an even number on at least one die. find

puteri [66]

We know P = 1/2

X~B(2, 0.5)
n = 1

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4 years ago

khan academy is giving me only this explanation but won't go into detail and I cannot understand it for the life of me. how do I

Setler [38]

Answer:

12 - 4i

Step-by-step explanation:

-2i ( 2+6i)

Distribute

-2i * 2 + -2i *6i

-4i - 12 i^2

We know that i^2 = -1 so replace it

-4i - 12(-1)

-4i + 12

Then put in the order a+bi where the real number comes first and the imaginary number comes last

12 - 4i

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3 years ago

3. A new process has been developed for applying pho toresist to 125-mm silicon wafers used in manufac turing integrated circu

dlinn [17]

Answer:

The null hypothesis is $H_o : \mu = 13.4000$

The alternative hypothesis is $H_a : \mu \ne 13.4000$

The null hypothesis is rejected

The 99% confidence level is $13.3930 < \mu < 13.3994$

Step-by-step explanation:

From the question we are told that

The sample size is n = 10

The population mean is $\mu = 13.4 000 \ angstroms$

The level of significance is $\alpha = 0.05$

The sample data is

13.3987, 13.3957, 13.3902, 13.4015, 13.4001, 13.3918, 13.3965, 13.3925, 13.3946, and 13.4002

Generally the sample mean is mathematically represented as

$\= x = \frac{13.3987+ 13.3957\cdots +13.4002 }{10}$

=> $\= x = 13.3962$

Generally the sample standard deviation is mathematically represented as

$\sigma = \sqrt{\frac{\sum (x_i - \= x)^2}{n} }$

=> $\sigma = \sqrt{\frac{ (13.3987 - 13.3962)^2 + (13.3987 - 13.3962)^2 + \cdots + (13.3987 -13.4002)^2 }{10} }$

=> $\sigma =0.0039$

The null hypothesis is $H_o : \mu = 13.4000$

The alternative hypothesis is $H_a : \mu \ne 13.4000$

Generally the test statistics is mathematically represented as

$z = \frac{\= x - \mu}{\frac{\sigma}{\sqrt{n} } }$

=> $z = \frac{13.3962 - 13.4000}{\frac{0.0039}{\sqrt{10} } }$

=> $z = 3.08$

Generally the p-value is mathematically represented as

$p-value = 2P( z > 3.08)$

From the z-table $P(z > 3.08)= 0.001035$

$p-value = 2* 0.001035$

$p-value = 0.00207$

So from the obtained value we see that

$p-value < \alpha$

Hence the null hypothesis is rejected

Consider the b question

Given that the confidence level is 99% then the level of significance is

$\alpha = (100 -99)\%$

=> $\alpha = 0.01$

Generally from the normal distribution table critical value of $\frac{\alpha }{2}$ is

$Z_{\frac{\alpha }{2} } = 2.58$

Generally the margin of error is mathematically represented as

$E = Z_{\frac{\alpha }{2} } * \frac{\sigma}{\sqrt{n} }$

=> $E = 2.58 * \frac{0.0039}{\sqrt{10} }$

=> $E = 0.00318$

Generally the 99% confidence interval is mathematically represented as

$13.3962 - 0.00318 < \mu < 13.3962 + 0.00318$

=> $13.3930 < \mu < 13.3994$

7 0

3 years ago

? can guys help me please?

weqwewe [10]

Answer:

The range of this set of numbers is 9

Step-by-step explanation:

The range is the greatest number subtracted by the lowest number

in this problem that is 21-12

7 0

3 years ago

Read 2 more answers