Need help asap!!!!!!!!

Mathematics

1 answer:

dangina [55]3 years ago

4 0

This is a rectangle plus a semicircle. We're only asked for the area of the semicircle; if they were better question writers they would have included an answer that's the area of the entire shape. Amateurs.

The semicircle has a diameter of 3 feet, so a radius of 1.5 feet and an area of

$\frac 1 2 \pi r^2 = \frac 1 2 \pi (1.5)^2 \approx 3.534$

First choice. The half in the formula comes from the fact we want the area of a semicircle.

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Please help I can’t figure this out!

Monica [59]

Explanation:

All values in the x-column get filled with -2.

The graph is the vertical line, x = -2.

You are told x=-2. There is nothing to figure out. The value of y is irrelevant.

That equation describes a vertical line. The points on the line have x-coordinate -2, and any (every) y-coordinate.

4 0

2 years ago

In a completely randomized experimental design, three brands of paper towels were tested for their ability to absorb water. Equa

arlik [135]

Answer:

Yes. At this significance level, there is evidence to support the claim that there is a difference in the ability of the brands to absorb water.

Step-by-step explanation:

The question is incomplete:

The significance level is 0.05.

The data is:

Brand X: 91, 100, 88, 89

Brand Y: 99, 96, 94, 99

Brand Z: 83, 88, 89, 76

We have to check if there is a significant difference between the absorbency rating of each brand.

Null hypothesis: all means are equal

$H_0:\mu_x=\mu_y=\mu_z$

Alternative hypothesis: the means are not equal

$H_a: \mu_x\neq\mu_y\neq\mu_z$

We have to apply a one-way ANOVA

We start by calculating the standard deviation for each brand:

$s_x^2=30,\,\,s_y^2=6,\,\,s_z^2=35.33$

Then, we calculate the mean standard error (MSE):

$MSE=(\sum s_i^2)/a=(30+6+35.33)/3=71.33/3=23.78$

Now, we calculate the mean square between (MSB), but we previously have to know the sample means and the mean of the sample means:

$M_x=92,\,\,M_y=97,\,\,M_z=84\\\\M=(92+97+84)/3=91$

The MSB is then:

$s^2=\dfrac{\sum(M_i-M)^2}{N-1}\\\\\\s^2=\dfrac{(92-91)^2+(97-91)^2+(84-91)^2}{3-1}\\\\\\s^2=\dfrac{1+36+49}{2}=\dfrac{86}{2}=43\\\\\\\\MSB=ns^2=4*43=172$