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3 years ago

Complete the problems. Check your answers in the back o

Mathematics

1 answer:

gayaneshka [121]3 years ago

6 0

1. 40/100(70) = 28
2. 25/100(120) = 30
3. 5/100(30) = 3/2
4. 145/100(200) = 290

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The measured length is 250 ft. The actual length is 246.9 ft. Find the percent error.

Marta_Voda [28]

Percent error = 1.2556%

Steps:
Percent Error =
Vobserved - Vtrue
Vtrue
=
250 - 246.9
246.9
=
3.1
246.9
= 1.2555690562981%

7 0

3 years ago

What is the value of a in the equation 5a – 10b = 45, when b = 3?

lara31 [8.8K]

Here you go. Do you think that you could help me with my question

5a – 10b = 45
5a – 10(3) = 45
5a – 30 = 45
+30 +30
5a = 75/5
a = 15

8 0

3 years ago

Read 2 more answers

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:

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

Now we calculate the F statistic as:

$F=MSB/MSE=172/23.78=7.23$

The degrees of freedom of the numerator are:

$dfn=a-1=3-1=2$

The degrees of freedom of the denominator are:

$dfd=N-a=3*4-3=12-3=9$

The P-value of F=7.23, dfn=2 and dfd=9 is:

$P-value=P(F>7.23)=0.01342$

As the P-value (0.013) is smaller than the significance level (0.05), the null hypothesis is rejected.

There is evidence to support the claim that there is a difference in the ability of the brands to absorb water.

3 0

3 years ago

If the center of a circle is (-5,8) and a point on the circle is (-5, -4) What is the radius?

Maslowich

Answer:

The radius is 12.

Step-by-step explanation:

You're given the center and a point on the circle. The point and the center both have an x-coordinate of -5, so there is no horizontal distance between them. The distance is only in the vertical direction. The distance from 8 to -4 is 12. Since this is the distance from the center to a point on the circle, this equals the radius.

3 0

3 years ago

The sum of two numbers is 42 and the difference is 14 . What are the numbers?

Nezavi [6.7K]

Answer:

28 and 14

Step-by-step explanation:

28+14= 42

28-14=14

3 0

3 years ago

Read 2 more answers