Write a Let" statement for the unknown, write an equation, and solve the equation. 11. Jane bought a number of records for $7 ea
1 answer:
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Answer:
0.3821 = 38.21% probability that no less than 95 out of 152 registered voters will vote in the presidential election.
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 distributions 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 ,
.
Assume the probability that a given registered voter will vote in the presidential election is 61%.
This means that
152 registed voters:
This means that
Mean and Standard deviation:
Probability that no less than 95 out of 152 registered voters will vote in the presidential election.
This is, using continuity correction, , which is 1 subtracted by the pvalue of Z when X = 94.5. So
has a pvalue of 0.6179
1 - 0.6179 = 0.3821
0.3821 = 38.21% probability that no less than 95 out of 152 registered voters will vote in the presidential election.
Answer:
The coordinates of point B are (-2, 2)
Step-by-step explanation:
We have two points: A and C.
The coordinates for A are (2, -8) and the coordinates for C are (-4, 7).
We have to find the coordinates of the point B, that satisfies the condition that the distance AB is 2 times the distance BC.
We also know that B is a point of the line AC.
We can calculate the line AC as a linear function y=mx+b.
The slope m is:
Then, the y-intercept b can be calculated using the coordinates of one of the points, in this case point A:
Then, we know that B is a point of the linear function y=-2.5x-3, within the range x ∈ (-4; 2).
To have a ratio AB to BC of 2 to 1, we can divide the length of the line AC in 3 parts, and the point B will be located in the end of the segment nearer to point C.
In the picture attached, you can see the division of the segment AC in three parts and the location of point B=(x, y).
Applying the Thales theorem, we can divide the segment in the y-axis in three and calculate y, and the same for the x-axis.
Then, the coordinate y for the point B is:
Then, the point B has coordinates (-2, 2).
We can verify the distances as:
