$\bf \qquad \qquad \textit{direct proportional variation}\\\\
\textit{\underline{y} varies directly with \underline{x}}\qquad \qquad y=kx\impliedby 
\begin{array}{llll}
k=constant\ of\\
\qquad variation
\end{array}\\\\
-------------------------------\\\\
(\stackrel{x}{8}~~,~~\stackrel{y}{4})\implies 
\begin{cases}
x=8\\
y=4
\end{cases}\implies 4=k8\implies \cfrac{4}{8}=k\implies \cfrac{1}{2}=k
\\\\\\
\boxed{y=\cfrac{1}{2}x}$

6 0

3 years ago

what are the lengths of the legs of a right triangle in which one acute angle measures 19° and the hypotensue is 15 units long?

givi [52]

Refer to the diagram shown below.

Given:
m∠A = 19°
c = 15

By definition,
sin A = a/c
Therefore
a = c*sin A = 15*sin(19°) = 4.8835

cos A = b/c
Therefore
b = c*cos A = 15*cos(19°) =14.1828

Answer:
The lengths are 4.88, 14.18, and 15.00 (nearest hundredth)

6 0

3 years ago

A researcher compares differences in positivity between participants in a low-, middle-, or upper-middle-class family. If she ob

777dan777 [17]

Answer:

(2, 12)

Step-by-step explanation:

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"

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

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

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

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

And we have this property

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

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

The degrees of freedom for the denominator on this case is given by $df_{den}=df_{between}=N-K=15-3=12$ .

And the total degrees of freedom would be $df=N-1=15 -1 =14$

And the correct answer would be 2 degrees of freedom for the numerator and 12 for the denominator

(2, 12)

3 0

3 years ago

It took 12 kg of rope to fill box A about how many kg of rope woulf it take to fill box B ​

It took 12 kg of rope to fill box A about how many kg of rope woulf it take to fill box B