Answer: 21
Step-by-step explanation:
Given : The scores on the midterm exam are normally distributed with
Let X be random variable that represents the score of the students.
z-score:
For x=82
For x=90
Now, the probability of the students in the class receive a score between 82 and 90 ( by using standard normal distribution table ) :-
Now ,the number of students expected to receive a score between 82 and 90 are :-
Hence, 21 students are expected to receive a score between 82 and 90 .
Answer:
Step-by-step explanation:
We note that the coefficient of y in equation (iii) is 1, so it is convenient to use that equation to eliminate y from the others.
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<em>To eliminate the y-variable from equation (i), four times equation (iii) can be added to equation (i).</em>
<em>To eliminate the y-variable from equation (ii), three times equation (iii) can be subtracted from equation (i).</em>
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The result of these operations would be ...
Answer:
B.The probability 0+ indicates that the probability is a very small positive value. It indicates that the event is possible, but very unlikely.
Step-by-step explanation:
Out of 1009 consumers a sample of 30 consumers is selected and asked the questions. So, the sample size is 30.
n = 30
Based on previous survey, 42% are comfortable with the drone. So in this sample, we can consider the probability of success to be 42%.
p = 42% = 0.42
q = 1 - p = 1 - 0.42 = 0.58
We want to find the probability of getting exactly 24 consumers who are comfortable with drones.
x = 24
Since, the sample size is fixed, the selections are independent and probability of success is constant, we can use the Binomial Probability to answer this problem. All the conditions of a Binomial Distribution are being satisfied.
According to the formula of Binomial Distribution, the probability of getting exactly x success among n trials is given as:
Using the values, we get:
Thus, the probability of getting exactly 24 consumers from a sample of 30 who are comfortable with drones is 0.00002, which is extremely small.
Since, the value of probability is a very small positive number, it indicates that event is possible but very unlikely. An impossible event has probability equal to 0.
Therefore, option B gives the correct answer.