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2 years ago

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A problem states that Ursula earns $9 per hour. To write an expression that tells how much money Ursula earns for h hours, Joshu

a wrote 9 divided by h. Sarah wrote 9h. Whose expression is correct and why?

1 answer:

LekaFEV [45]2 years ago

8 0

The correct one would by 9h because you are asking how much will Ursula make per hour. So let's say that h is 10, then in order to know how much Ursula makes per hour, you have to add 9 ten times. A short way to do that would be to simply multiply 9 with 10 so that you can get the answer of 90. It cannot be 9/h because then answer will be much lower than it is supposed to be. So the answer to the question is really 9h.

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An isosceles triangle has two sides of equal length, a, and a base, b. The perimeter of the triangle is 15.7 inches, so the equa

yarga [219]

Answer:

[c] The value of w cannot be a negative number.

[d] Substitution is used to replace the variable l with a value of 20.

[e] The subtraction property of equality is used to isolate the term with the variable w.

Step-by-step explanation:

To figure out which steps of the solution are true, let us solve.

2 l plus 2 w equals 62 -> 2l + 2w = 62

----

2l + 2w = 62

2(20) + 2w = 62 <- Substitution is used to replace the variable l with a value of 20.

40 + 2w = 62

2w = 22 <- The subtraction property of equality is used to isolate the term with the variable w.

w = 11

This means that the value of w is <em>not</em> 10 feet so the first option is incorrect. This shape is a rectangle, so the value of w cannot be 0. Since we cannot have a negative measurement, option three is incorrect. This leaves us with the last three options as our answer, shown by the work above.

<em> Read more about </em><em>this question</em><em> here:</em>

<em>brainly.com/question/12856278</em>

6 0

1 year ago

How do I get X for this question?

exis [7]

Answer:

The value of x is 12

Step-by-step explanation:

To find the value of x, we need to note that the interior angles are equal to 180. We also know that angle R is equal to 180 - (8 + 6x). So we can add all of this together and set equal to 180.

180 - (8 + 6x) + 4x + 2 + 30 = 180

180 - 8 - 6x + 4x + 2 + 30 = 180

-2x + 24 = 0

-2x = -24

x = 12

7 0

3 years ago

Three assembly lines are used to produce a certain component for an airliner. To examine the production rate, a random

Katyanochek1 [597]

Answer:

a) Null hypothesis: $\mu_A =\mu_B =\mu C$

Alternative hypothesis: $\mu_i \neq \mu_j, i,j=A,B,C$

$SS_{total}=\sum_{j=1}^p \sum_{i=1}^{n_j} (x_{ij}-\bar x)^2 =20.5$

$SS_{between}=SS_{model}=\sum_{j=1}^p n_j (\bar x_{j}-\bar x)^2 =12.333$

$SS_{within}=SS_{error}=\sum_{j=1}^p \sum_{i=1}^{n_j} (x_{ij}-\bar x_j)^2 =8.16667$

And we have this property

$SST=SS_{between}+SS_{within}$

The degrees of freedom for the numerator on this case is given by $df_{num}=df_{within}=k-1=3-1=2$ where k =3 represent the number of groups.

The degrees of freedom for the denominator on this case is given by $df_{den}=df_{between}=N-K=3*6-3=15$ .

And the total degrees of freedom would be $df=N-1=3*6 -1 =15$

The mean squares between groups are given by:

$MS_{between}= \frac{SS_{between}}{k-1}= \frac{12.333}{2}=6.166$

And the mean squares within are:

$MS_{within}= \frac{SS_{within}}{N-k}= \frac{8.1667}{15}=0.544$

And the F statistic is given by:

$F = \frac{MS_{betw}}{MS_{with}}= \frac{6.166}{0.544}= 11.326$

And the p value is given by:

$p_v= P(F_{2,15} >11.326) = 0.00105$

So then since the p value is lower then the significance level we have enough evidence to reject the null hypothesis and we conclude that we have at least on mean different between the 3 groups.

b) $(\bar X_B -\bar X_C) \pm t_{\alpha/2} \sqrt{\frac{s^2_B}{n_B} +\frac{s^2_C}{n_C}}$

The degrees of freedom are given by:

$df = n_B +n_C -2= 6+6-2=10$

The confidence level is 99% so then $\alpha=1-0.99=0.01$ and $\alpha/2 =0.005$ and the critical value would be: $t_{\alpha/2}=3.169$

The confidence interval would be given by:

$(43.333 -41.5) - 3.169 \sqrt{\frac{0.6667}{6} +\frac{0.7}{6}}= 0.321$

$(43.333 -41.5) + 3.169 \sqrt{\frac{0.6667}{6} +\frac{0.7}{6}}=3.345$

Step-by-step explanation:

Previous concepts

Analysis of variance (ANOVA) "is used to analyze the differences among group means in a sample".

The sum of squares "is the sum of the square of variation, where variation is defined as the spread between each individual value and the grand mean"

Part a

Null hypothesis: $\mu_A =\mu_B =\mu C$

Alternative hypothesis: $\mu_i \neq \mu_j, i,j=A,B,C$

If we assume that we have $3$ groups and on each group from $j=1,\dots,6$ we have $6$ individuals on each group we can define the following formulas of variation:

$SS_{total}=\sum_{j=1}^p \sum_{i=1}^{n_j} (x_{ij}-\bar x)^2 =20.5$

$SS_{between}=SS_{model}=\sum_{j=1}^p n_j (\bar x_{j}-\bar x)^2 =12.333$

$SS_{within}=SS_{error}=\sum_{j=1}^p \sum_{i=1}^{n_j} (x_{ij}-\bar x_j)^2 =8.16667$

And we have this property

$SST=SS_{between}+SS_{within}$

The degrees of freedom for the numerator on this case is given by $df_{num}=df_{within}=k-1=3-1=2$ where k =3 represent the number of groups.

The degrees of freedom for the denominator on this case is given by $df_{den}=df_{between}=N-K=3*6-3=15$ .

And the total degrees of freedom would be $df=N-1=3*6 -1 =15$

The mean squares between groups are given by:

$MS_{between}= \frac{SS_{between}}{k-1}= \frac{12.333}{2}=6.166$

And the mean squares within are:

$MS_{within}= \frac{SS_{within}}{N-k}= \frac{8.1667}{15}=0.544$

And the F statistic is given by:

$F = \frac{MS_{betw}}{MS_{with}}= \frac{6.166}{0.544}= 11.326$

And the p value is given by:

$p_v= P(F_{2,15} >11.326) = 0.00105$

So then since the p value is lower then the significance level we have enough evidence to reject the null hypothesis and we conclude that we have at least on mean different between the 3 groups.

Part b

For this case the confidence interval for the difference woud be given by:

$(\bar X_B -\bar X_C) \pm t_{\alpha/2} \sqrt{\frac{s^2_B}{n_B} +\frac{s^2_C}{n_C}}$

The degrees of freedom are given by:

$df = n_B +n_C -2= 6+6-2=10$

The confidence level is 99% so then $\alpha=1-0.99=0.01$ and $\alpha/2 =0.005$ and the critical value would be: $t_{\alpha/2}=3.169$

The confidence interval would be given by:

$(43.333 -41.5) - 3.169 \sqrt{\frac{0.6667}{6} +\frac{0.7}{6}}= 0.321$

$(43.333 -41.5) + 3.169 \sqrt{\frac{0.6667}{6} +\frac{0.7}{6}}=3.345$

7 0

2 years ago

8 grams = milligrams

Digiron [165]

Answer:

8,000 miligrams

Step-by-step explanation:

There's 1000 milligrams in a gram so you would have to do multiplication.

which if you do..

8x1000

you should get...

8000 milligrams

4 0

2 years ago

Read 2 more answers

The mass of Earth is 5.97 >< 1024 kilograms. The mass of the Moon is 7.34 x 1022 kilograms. What is the combined mass of E

LuckyWell [14K]

Answer:

7.34x10^22 kg can also be written as 0.0734 * 10^24 kg

Since both numbers are * 10^24, you can just add 5.97 + 0.0734 = 6.043. Then you have to add the * 10^24 giving you 6.043 * 10^24 kg

The ratio of Earth / moon is 5.97x10^24 / 7.34x10^22 = 81. The mass of the Earth is 81 times the mass of the moon.

Step-by-step explanation: give me brainliest please :)

6 0

2 years ago