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Inessa05 [86]
3 years ago
8

Calculate the average speed of a train that

Mathematics
1 answer:
lorasvet [3.4K]3 years ago
4 0

Answer:

4

Step-by-step explanation:

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People tend to evaluate the quality of their lives relative to others around them (Frieswijk et al., 2004). In one study, resear
Alborosie

Answer:

Step-by-step explanation:

Hello!

Research.

n=9 frail elderly were interview and compared to a fictitious person who was worse off then the interviewee, a life-satisfaction score was determined for each person.

18, 23, 24, 22, 19, 27, 23, 26, 25

Assuming that the population average score is μ= 20, the researchers think that the elderly in the sample are more or less satisfied than others in the general population.

a. You have the information of one sample, assuming this sample has a normal distribution and each elderly interviewed is independent, then the t-test of choice is a one-sample t-test.

b. and c. If you say that the elderly are "more or less" satisfied than the others, this means that they are either as satisfied as to the general population or not satisfied as to the general population. Symbolically:

H₀: μ = 20

H₁: μ ≠ 20

This is a two-tailed test, meaning, you will have two critical regions.

d.  

α: 0.05

Left critical value: t_{n-1;/\alpha 2} = t_{8; 0.025}= -2.306

Right critical value: t_{n-1;1-\alpha /2} = t_{8;0.975} = 2.306

e.

t_{H_0}= \frac{X[bar]-Mu}{\frac{S}{\sqrt{n} } } ~t_{n-1}

X[bar]= 23

S= 3

t_{H_0}= \frac{23-20}{\frac{3}{\sqrt{9} } }= 3

f.

Considering that the calculated t-value is greater than the right critical value, the decision is to reject the null hypothesis, so using a significance level of 5% you can conclude that the average life-satisfaction score of the elderly is different than 20.

I hope it helps!

7 0
3 years ago
when two trucks traveling in different directions approach each an intersection at the same time , on of the trucks must change
torisob [31]

This happens because the trucks move in one-dimension, while the airplanes move in 3 dimensions.

<h3></h3><h3>Why the trucks need to change direction or speed while the airplanes don't?</h3>

Well, the trucks move along a street. Thus, we can think that this is an one-dimensional kind of motion.

Where the trucks can go forward, backward, or get out of the line.

In the case of the airplanes, they can move actually in 3 dimensions (the airplane can go upwards, downwards, left, right, etc).

Now, in the one-dimensional case of the trucks there are only two directions (which are opposite) so if the trucks travel in different directions, then the trucks travel into each other, which would cause the collision.

While in the case of the airplanes more directions exists, so there isn't (necessarily) a collision.

If you want to learn more about motion:

brainly.com/question/26048315

#SPJ1

4 0
2 years ago
Solve 2(x+3)3/2=54 x = <br>show your work
hjlf

Answer:

x=15

Step-by-step explanation:

Step 1: Multiply both sides by 2.

Step 2: Simplify both sides of the equation.

6x+18=108

Step 3: Subtract 18 from both sides.

6x+18−18=108−18

6x=90

Step 4: Divide both sides by 6.

x=15

6 0
3 years ago
A frame shop owner is working with her apprentice, who takes four times as long as
Lunna [17]

Answer:

1 hour

Step-by-step explanation:

25min=1 poster for the shop owner

25×4=100

100×8=800

800÷25=32 posters in 8hrs for the shop owner

1hr×8=8 posters for the apprentice

thus 40 in total

6 0
3 years ago
mean of 164,175,178,166,167,145,176,150,174,162,180,156,173,158,182,184,160,172,186,168,195,169,171,187,170
Karo-lina-s [1.5K]

Answer:

170.72

Step-by-step explanation:

to find the mean, we must add al the numbers and divide it by n

that is,

164,175,178,166,167,145,176,150,174,162,180,156,173,158,182,184,160,172,186,168,195,169,171,187,170 we have to add al these numbers and divide it by 25

sum- 4628 divided by 25

=170.72

7 0
1 year ago
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