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Cumulative Distribution Function

     A cumulative distribution function (CDF) is a distribution function for a random variable X that gives the probability that it will be less than or equal to a value x. That is to say that the cumulative distribution function can be defined formulaically as:

An example of a CDF graph would look like such:

     For example, if we were to ask for CDF(0.5), we would find that it is equal to approximately 0.72 as shown by the dotted red line. This means that the probability for the variable X to be less than or equal to 0.5 is 0.72. Consequently the final point on the CDF will always be equal to one, because it is the probability that X will be less than or equal to its maximum value; the answer must be 100%. CDF's can be used to answer questions such as "What is the chance I will get at least 70% on this test? at least 80%? 90%?"



The Normal Distribution and Confidence Intervals

Basic Statistics Name: Test 2- The Normal Distribution and Confidence Intervals 1) Assume that the distribution of heights of adult American men is normally distributed with mean 69 inches and standard deviation 2.8 inches. A Carefully label the x- and z-axes of the normal distribution. B. What percentage of men i

Statistics: Binominal Distribution with Continuity Correlation for fair coin toss

Suppose a fair coin is tossed n times. The probability of obtaining head and tail are the same because this is a fair coin. The proportion of heads is defined as the number of heads appeared divided by n. We can model this probability distribution by binominal distribution. For large n, the binominal distribution can be repla

Give a mathematical expression for the probability density function of driving distance. Suppose you bid $12,000. What is the probability that you bid will accepted? What is the probability the random variable will assume a value between 45 and 55? Assume that the class has 60 students and that the examination period is 90 minutes in length. How many students do you expect will be unable to complete the exam in the allotted time?

5. The driving distance for the top 100 golfers on the PGA tour is between 284.7 and 310.6 yards (Golfweek,March 29,2003). Assume that the driving distance for these golfers is uniformly distributed over this interval. a. Give a mathematical expression for the probability density function of driving distance. b. What is the pr

Probability : Acceptable Range of Values and Cumulative Distribution Function

1) A manufacturer of flashlight batteries wishes to control the quality of its product by rejecting any lot in which the proportion of batteries having unacceptable voltage appears to be too high. To this end, out of each large lot (10,000 batteries), 25 will be selected and tested. If at least 5 of these generate an unacceptab

Cumulative Distribution Function

The attachment represents the cumulative dist. funct. for a random variable x. From the graph, find P(2<=x<=3): Must be one of the following answers: a.) 0.6 b.) 0.2 c.) 0.4 d.) 0.8

Summarize the data by construction the following: a frequency distribution, a relative frequency distribution, a cumulative frequency distribution, a cumulative relative frequency distribution and an ogive. Describe the pattern in the graph for the problem. Compute appropriate summary statistics for the data in problem.

19. The data for the numbers of units produced by a production employee during the most recent 20 days are shown here. 160 170 181 156 176 148 198 179 162 150 162 156 179 178 151 157 154 179 148 156 Summarize the data by construction the following: a. a frequency distribution b. a relat