Answer:
P (X ≤ 4)
Step-by-step explanation:
The binomial probability formula can be used to find the probability of a binomial experiment for a specific number of successes. It <em>does not</em> find the probability for a <em>range</em> of successes, as in this case.
The <em>range</em> "x≤4" means x = 0 <em>or</em> x = 1 <em>or </em>x = 2 <em>or</em> x = 3 <em>or</em> x = 4, so there are five different probability calculations to do.
To to find the total probability, we use the addition rule that states that the probabilities of different events can be added to find the probability for the entire set of events only if the events are <em>Mutually Exclusive</em>. The outcomes of a binomial experiment are mutually exclusive for any value of x between zero and n, as long as n and p don't change, so we're allowed to add the five calculated probabilities together to find the total probability.
The probability that x ≤ 4 can be written as P (X ≤ 4) or as P (X = 0 or X = 1 or X = 2 or X = 3 or X = 4) which means (because of the addition rule) that P(x ≤ 4) = P(x = 0) + P(x = 1) + P (x = 2) + P (x = 3) + P (x = 4)
Therefore, the probability of x<4 successes is P (X ≤ 4)
Answer:
1) c/d = pi
Step-by-step explanation:
since c= pi x d
divide both sides by d
c/d = pi
Answer:
5.48% of the people in line waited for more than 28 minutes
Step-by-step explanation:
Normal Probability Distribution:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean
and standard deviation
, the z-score 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 p-value, we get the probability that the value of the measure is greater than X.
Mean waiting time of 20 minutes with a standard deviation of 5 minutes.
This means that 
What percentage of the people in line waited for more than 28 minutes?
The proportion is 1 subtracted by the p-value of Z when X = 28. So



has a p-value of 0.9452.
1 - 0.9452 = 0.0548.
As a percentage:
0.0548*100% = 5.48%
5.48% of the people in line waited for more than 28 minutes
Answer:
Please refer to the attachment
Answer:
77.8% is the answer hope it helps. its actually 77.777777778 but its to nearest tenth so round up