In the table, x represents the age in years of a collectible baseball card, and y represents its value in dollars. Cost of a Pac
2 answers:
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Answer:
a) distance halfway = 16.49 [m], displacement halfway = 10.5 [m]
b) distrance traveled increases when the child completes one circuit of the track.
Step-by-step explanation:
a) Distance is a scalar quantity that tells you how much space a body has covered when moving. Displacement is a vector quantity that tells you how far from its initial position and object is after moving.
In this case, the child goes around the track only halfway from point 1 to point 2. We know the circunference or perimeter of a circle to be 2*PI*radius. We also know the child only when halfway, so we need to divide the perimeter by 2, thus we get distance = PI*radius
- distance halfway = (PI)*(5.25) = 16.49 [m]
And now that we know the definition of displacement, we can easily see that the child went from point 1 to point 2 which is located at a distance of 1 diameter from point 1:
- displacement halfway = D = 2*radius = 2(5.25) = 10.5 [m]
b)What happens to the distance when the child completes one circuit? The distance will increase beause he is now completing the circuit so he is covering more ground in his movement:
- distance circuit = 2*(PI)*radius = 2(PI)(5.25) = 32.99 [m]
32.99 is more than 16.49 so we are certain that the distance increases.
Answer:
Step-by-step explanation:
Hello!
To test if boys are better in math classes than girls two random samples were taken:
Sample 1
X₁: score of a boy in calculus
n₁= 15
X[bar]₁= 82.3%
S₁= 5.6%
Sample 2
X₂: Score in the calculus of a girl
n₂= 12
X[bar]₂= 81.2%
S₂= 6.7%
To estimate per CI the difference between the mean percentage that boys obtained in calculus and the mean percentage that girls obtained in calculus, you need that both variables of interest come from normal populations.
To be able to use a pooled variance t-test you have to also assume that the population variances, although unknown, are equal.
Then you can calculate the interval as:
[(X[bar]_1-X[bar_2) ± *
]
[(82.3-81.2) ± 1.708* (6.11*]
[-2.94; 5.14]
Using a 90% confidence level you'd expect the interval [-2.94; 5.14] to contain the true value of the difference between the average percentage obtained in calculus by boys and the average percentage obtained in calculus by girls.
I hope this helps!