Answer:
Step-by-step explanation:
When making a right triangle with 2 points, the distance is the hypotenuse which can be represent as "x"
To find the distance we can use the Pythagorean theorem.
→
→
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<u>Let's Plug in the side lengths:</u>
<u>Evaluate 9²= </u><u>81</u><u> and 2²= </u><u>4</u><u>:</u>
<u>Now, add 81+4= 85</u>
<u>Take the square root of both sides:</u>
_____________________________
Answer:
C. 0.896
Step-by-step explanation:
We use the binomial approximation to the normal to solve this question.
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:
So
What is the probability that at least seventy percent of the sample prefers Coke to Pepsi?
0.7*80 = 56.
This probability is 1 subtracted by the pvalue of Z when X = 56. So
has a pvalue of 0.1040.
1 - 0.1040 = 0.8960
So the correct answer is:
C. 0.896
