(3x + 1) (2x + 5x – 7)<br> Multiply

A contractor bought 10.8 ft squared of sheet metal. has used 2.1 ft squared so far and has $139.20 worth of sheet metal remaini

Anuta_ua [19.1K]

Answer:

7.1

Step-by-step explanation:

5 0

3 years ago

Read 2 more answers

Each cube in the prism is one cubic unit. <br> What is the volume of this rectangular prism?

Oksanka [162]

Answer:

I think the answer would be 120 cm3 .

8 0

3 years ago

What is 5/8 divided by 1/4

Llana [10]

Answer:

Exact form: 5/2

Decimal form: 2.5

Mixed number form: 2 and 1/2

Step-by-step explanation:

when you divide a fraction you keep, change, flip

Equation: 5/8 ÷ 1/4

keep 5/8 the same

change the divide symbol into a multipulcation symbol

flip 1/4 the other way, so it's 4/1 (it's a whole number now)

then just multiply across

Equation now: 5/8 × 4/1

6 0

3 years ago

The following data lists the ages of a random selection of actresses when they won an award in the category of Best Actress, al

Valentin [98]

Answer:

a) $p_v =P(t_{(9)}$

The p value is higher than the significance level given 0.01, so then we can conclude that we FAIL to reject the null hypothesis. And we can say that the true difference for Best Actresses is not significantly lower than the mean for Best Actors at 1% of significance.

b) The 99% confidence interval would be given by (-21.469;2.069)

c) We got the same conclusion as part a, sicne the confidence interval contains the value 0, we FAIL to reject the null hypothesis that the difference between the two

Step-by-step explanation:

Part a

Let put some notation

x=actor's age , y = actress's age

x: 58 41 36 36 34 33 48 37 37 43

y: 26 27 34 26 35 29 23 42 30 34

The system of hypothesis for this case are:

Null hypothesis: $\mu_y- \mu_x \geq 0$

Alternative hypothesis: $\mu_y -\mu_x$

The first step is calculate the difference $d_i=y_i-x_i$ and we obtain this:

d: -32, -14, -2, -10, 1, -4, -25, 5, -7, -9

The second step is calculate the mean difference

$\bar d= \frac{\sum_{i=1}^n d_i}{n}= -9.7$

The third step would be calculate the standard deviation for the differences, and we got:

$s_d =\frac{\sum_{i=1}^n (d_i -\bar d)^2}{n-1} =11.451$

The 4 step is calculate the statistic given by :

$t=\frac{\bar d -0}{\frac{s_d}{\sqrt{n}}}=\frac{-9.7 -0}{\frac{11.451}{\sqrt{10}}}=-2.679$

The next step is calculate the degrees of freedom given by:

$df=n-1=10-1=9$

Now we can calculate the p value, since we have a left tailed test the p value is given by:

$p_v =P(t_{(9)}$

The p value is higher than the significance level given 0.01, so then we can conclude that we FAIL to reject the null hypothesis. And we can say that the true difference for Best Actresses is not significantly lower than the mean for Best Actors at 1% of significance.

Part b

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".

The confidence interval for the mean is given by the following formula:

$\bar d \pm t_{\alpha/2}\frac{s}{\sqrt{n}}$ (1)

Since the Confidence is 0.99 or 99%, the value of $\alpha=0.01$ and $\alpha/2 =0.005$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-T.INV(0.005,9)".And we see that $t_{\alpha/2}=3.25$

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

$-9.7-3.25\frac{11.451}{\sqrt{10}}=-21.469$

$-9.7+3.25\frac{11.451}{\sqrt{10}}=2.069$

So on this case the 99% confidence interval would be given by (-21.469;2.069)

Part c

We got the same conclusion as part a, sicne the confidence interval contains the value 0, we FAIL to reject the null hypothesis that the difference between the two means is 0.

8 0

3 years ago

Determine if Ginny factored correctly. If not, explain where she made an error. Ginny made a mistake in step 1 when she identifi

il63 [147K]

Quadratic equations are second-order equations. Ginney made a mistake when she identified b = 31. It should be b = –31.

<h3>What is a Quadratic Equation?</h3>

A quadratic equation is an equation that can be written in the form of

ax²+bx+c.

Where a is the leading coefficient, and

c is the constant.

In order to find the mistake that Ginny made, we will first find the factors ourselves, therefore, we will factorize the trinomial,

$6x^2 - 31x -30 = 0$

As we can see that the value of constants are,

a = 6

b = -31

c = 30

$6x^2 - 31x -30 = 0\\\\6x^2 - 36x+5x -30 = 0\\\\6x(x-6)+5(x-6)=0\\\\(6x+5)(x-6)=0$

Therefore, the factors of the trinomial $6x^2 - 31x -30 = 0$ are (6x+5) and (x-6).

If we compare our process with Ginny's process, we will find that she has taken the value of the constant b as 31 which is wrong.

Hence, Ginney made a mistake when she identified b = 31. It should be b = –31.

Learn more about Quadratic Equation:

brainly.com/question/17177510

3 0

3 years ago

Read 2 more answers

(3x + 1) (2x + 5x – 7) Multiply