Noelle stands at the edge of a cliff and drops a rock. The height of the rock is given by the function f(x)-4.9x2 + 15, where c
is the number of seconds after noelle releases her rock.
Cesar, who is standing nearby on the ground, throws a rock straight up in the air. The height of Cesar’s rock is given by the function g(x)-4.9x2+10x, where x is the number of seconds after he releases his rock.
What is the height the money the two rocks are at the same level above ground.
Cesar, who is standing nearby on the ground, throws a rock straight up in the air. The height of Cesar’s rock is given by the function g(x)-4.9x2+10x, where x is the number of seconds after he releases his rock.
What is the height the money the two rocks are at the same level above ground.
1 answer:
A graphing calculator shows the rocks are at the same height 1.5 seconds after they are released.
That height is 3.975 meters.
_____
f(x) = g(x)
-4.9x^2 +15 = -4.9x^2 +10x
15 = 10x . . . . . . . . . . . . . . . . . . add 4.9x^2
1.5 = x . . . . . . . . . . . . . . . . . . . divide by 10
f(1.5) = -4.9*2.25 +15 = 3.975
That height is 3.975 meters.
_____
f(x) = g(x)
-4.9x^2 +15 = -4.9x^2 +10x
15 = 10x . . . . . . . . . . . . . . . . . . add 4.9x^2
1.5 = x . . . . . . . . . . . . . . . . . . . divide by 10
f(1.5) = -4.9*2.25 +15 = 3.975
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Answer:
The answer in the procedure
Step-by-step explanation:
Let
A1 ------> the area of the first square painting
A2 ----> the area of the second square painting
D -----> the difference of the areas
we have
case 1) The area of the second square painting is greater than the area of the first square painting
The difference of the area of the paintings is equal to subtract the area of the first square painting from the area of the second square painting
D=A2-A1
case 2) The area of the first square painting is greater than the area of the second square painting
The difference of the area of the paintings is equal to subtract the area of the second square painting from the area of the first square painting
D=A1-A2
Answer:
a) 0.6628 = 66.28% probability that at least 85 visitors had a recorded entry through the Beaver Meadows park entrance
b) 0.5141 = 51.41% probability that at least 80 but less than 90 visitors had a recorded entry through the Beaver Meadows park entrance
c) 0.5596 = 55.96% probability that fewer than 12 visitors had a recorded entry through the Grand Lake park entrance.
d) 0.9978 = 99.78% probability that more than 55 visitors have no recorded point of entry
Step-by-step explanation:
Binomial probability distribution
Probability of exactly x sucesses on n repeated trials, with p probability.
Can be approximated to a normal distribution, using the expected value and the standard deviation.
The expected value of the binomial distribution is:
The standard deviation of the binomial distribution is:
Normal probability distribution
Problems of normally distributed samples can be solved using the z-score formula.
In a set with mean and standard deviation
, the zscore of a measure X is given by:
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
When we are approximating a binomial distribution to a normal one, we have that ,
.
In this problem, we have that:
(a) What is the probability that at least 85 visitors had a recorded entry through the Beaver Meadows park entrance?
46.7% of visitors to Rocky Mountain National Park in 2018 entered through the Beaver Meadows. This means that . So
This probability, using continuity correction, is , which is 1 subtracted by the pvalue of Z when X = 84.5. So
has a pvalue of 0.6628.
66.28% probability that at least 85 visitors had a recorded entry through the Beaver Meadows park entrance.
(b) What is the probability that at least 80 but less than 90 visitors had a recorded entry through the Beaver Meadows park entrance?
Using continuity correction, this is , which is the pvalue of Z when X = 89.5 subtracted by the pvalue of Z when X = 79.5. So
X = 89.5
has a pvalue of 0.8810.
X = 79.5
has a pvalue of 0.3669.
0.8810 - 0.3669 = 0.5141
51.41% probability that at least 80 but less than 90 visitors had a recorded entry through the Beaver Meadows park entrance
(c) What is the probability that fewer than 12 visitors had a recorded entry through the Grand Lake park entrance?
6.3% of visitors entered through the Grand Lake park entrance, which means that
This probability, using continuity correction, is , which is the pvalue of Z when X = 11.5. So
has a pvalue of 0.5596.
55.96% probability that fewer than 12 visitors had a recorded entry through the Grand Lake park entrance.
(d) What is the probability that more than 55 visitors have no recorded point of entry?
22.7% of visitors had no recorded point of entry to the park. This means that
Using continuity correction, this probability is , which is the pvalue of Z when X = 55.5. So
has a pvalue of 0.9978
0.9978 = 99.78% probability that more than 55 visitors have no recorded point of entry