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2 years ago

Simplify (4.5)(5)(−2). (1 point) a 45 b 4.5 c −4.5 d −45

Mathematics

1 answer:

loris [4]2 years ago

8 0

Answer:

D cause it equals -45

Step-by-step explanation:

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A coin is tossed and a number cube is rolled at the same time. What is the probability that the coin will land on tails and the

babymother [125]

A-1/12 because if you write down h1, h2, h3, etc.-same for tail….tail and four would show up once out of the twelve options.

8 0

2 years ago

1) -4.2 = y - 1.8<br> i don’t know the answer need help

anastassius [24]

Answer:

y - 1.8 = -4.2

y = -2.4 is the solution

4 0

3 years ago

Read 2 more answers

A random sample of size n1= 25, taken from a normal population with a standard deviation σ1= 5, has a mean X1= 80. A second rand

sesenic [268]

Answer:

The 94% confidence interval would be given by $2.898 \leq \mu_1 -\mu_2 \leq 7.102$

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

$\bar X_1 =80$ represent the sample mean 1

$\bar X_2 =75$ represent the sample mean 2

n1=25 represent the sample 1 size

n2=36 represent the sample 2 size

$\sigma_1 =5$ sample standard deviation for sample 1

$\sigma_2 =3$ sample standard deviation for sample 2

$\mu_1 -\mu_2$ parameter of interest.

The confidence interval for the difference of means is given by the following formula:

$(\bar X_1 -\bar X_2) \pm z_{\alpha/2}\sqrt{\frac{\sigma^2_1}{n_1}+\frac{\sigma^2_2}{n_2}}$ (1)

The point of estimate for $\mu_1 -\mu_2$ is just given by:

$\bar X_1 -\bar X_2 =80-75=5$

Since the Confidence is 0.94 or 94%, the value of $\alpha=0.06$ and $\alpha/2 =0.03$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-NORM.INV(0.03,0,1)".And we see that $z_{\alpha/2}=1.88$

The standard error is given by the following formula:

$SE=\sqrt{\frac{\sigma^2_1}{n_1}+\frac{\sigma^2_2}{n_2}}$

And replacing we have:

$SE=\sqrt{\frac{5^2}{25}+\frac{3^2}{36}}=1.118$

Confidence interval

Now we have everything in order to replace into formula (1):

$5-1.88\sqrt{\frac{5^2}{25}+\frac{3^2}{36}}=2.898$

$5+1.8\sqrt{\frac{6^2}{36}+\frac{7^}{49}}=7.102$

So on this case the 94% confidence interval would be given by $2.898 \leq \mu_1 -\mu_2 \leq 7.102$

7 0

3 years ago

If F (7) 22, Then F(f-1(22))

jeka57 [31]

Answer:

$\boxed{\boxed{f(f^{-1}(22))=22}}$

Step-by-step explanation:

$\text{If we have}\ f(x)\ \text{and}\ f^{-1}(x),\ \text{then}\\\\\text{if}\ f(a)=b,\ \text{then}\ f^{-1}(b)=a.\\\\\text{Therefore, if}\ f(7)=22,\ \text{then}\ f^{-1}(22)=7.\\\\f(\underbrace{f^{-1}(22)}_{=7})=f(7)=22$

6 0

3 years ago

(2x - 3)(4 - 3x) find the product of binomials

Sedbober [7]

Answer:

6x²+17x-12

Step-by-step explanation:

(2x-3)(4-3x)

8x-6x²-12+9x

Reorder.

6x²+9x+8x-12

Combine like terms.

6x²+17x-12

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hope it helps

8 0

3 years ago