Stats Help for College-level Students

Working with the Chi-Square Procedure.

Suppose that you want to decide whether the distribution of primary heating fuel of occupied housing units built after 1974 differs from that of all occupied housing units. To help you decide, you take a random sample of n housing units built after 1974 and obtain a frequency distribution of their primary heating fuel. The p ...continues

Calculations of mean, median, and mode.

Calculate mean, median, and mode. Graph the data and locate the averages. See attached file for full problem description.

Using the probability density function to find the cumulative distribution function of an exponentially distributed random variable.

You are told that the continuous random variable X is exponentially distributed with parameter a (a > 0). A standard result then says that the probability density function of X is (see attachment) f(x) = aexp(-ax) for x > 0. Use this to prove that the corresponding cumulative distribution function F(x) (sometimes referred ...continues

Probability

26. MCQ: A family center conducted research on carbohydrate consumption in the high school and found that 30% of all high school sophomores ate at least four candy bars a day. If 20 high school sophomores are selected at random, what is the probability that exactly 6 of these eat at least 4 candy bars a day? a) 0.300 b) ...continues

Probability: NBA (National Basketball Association) application

Probability questions on NBA. ONLY DO PROBLEM 1 and 2 from the four questions in the document. Problem 1 � Consider the NBA Data Set Given: A. What proportion of these players are less than 74 inches tall? B. Suppose a random sample of 25 of these players is taken and x is the number of players in the sample who are less ...continues

Multiple choice question about the mean of a distribution.

The number of cartoons watched by first graders on Saturday mornings is shown below: x, P(x) 0, 0.2 1, 0.2 2, 0.3 3, 0.15 4, 0.1 5, 0.05 The mean of this distribution is a) 1.9 b) 2.6 c) 2.4 d) 3.1 e) None of the above

True or false question about the area under a normal distribution curve.

True or false: The area under the normal distribution curve between z = 1.52 and z = 2.35 would be 0.0549.

Multiple Choice question about finding the mean from a normal distribution given standard deviation.

In a given normal distribution, the standard deviation is 14.4 and 8.27% of the distribution lies to the left of 60. What is the mean? a) 80 b) 40 c) 63 d) 72 e) None of the above

Multiple choice question about the area under a normal distribution curve.

What is the area under the normal distribution curve to the left of z = 0.87 ? a) 0.3078 b) 0.8078 c) 0.1922 d) 0.6922 e) None of the Above

Corresponding percentile of a z value

True or false. The z-value which corresponds to the 18th percentile is z = -0.92.