### Probability and Statistics: Exercises on Probability Distributions **Exercise 7.34** For a given computer salesperson, the probability distribution of \( x \), which is the number of systems sold in one month, is as follows: | \( x \) | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | |-------|----|----|----|----|----|----|----|----| | \( p(x) \) | 0.05 | 0.10 | 0.12 | 0.30 | 0.30 | 0.11 | 0.01 | 0.01 | - **a.** Calculate the mean value of \( x \) (the mean number of systems sold). - **b.** Determine the variance and standard deviation of \( x \). Provide an interpretation of these values. - **c.** Calculate the probability that the number of systems sold is within 1 standard deviation of its mean value. - **d.** Calculate the probability that the number of systems sold is more than 2 standard deviations from the mean. **Exercise 7.35** A local television station offers advertising spots of different lengths: 15-second, 30-second, and 60-second. Let \( x \) represent the length of a randomly selected commercial. The probability distribution is: | \( x \) | 15 | 30 | 60 | |-------|-----|-----|-----| | \( p(x) \) | 0.1 | 0.3 | 0.6 | - **a.** Find the average length of randomly selected advertising spots. This exercise set aims to strengthen your understanding of probability distributions, particularly focusing on calculating statistical measures such as mean, variance, and standard deviation, and understanding their implications in real-world scenarios.
Inverse Normal Distribution
The method used for finding the corresponding z-critical value in a normal distribution using the known probability is said to be an inverse normal distribution. The inverse normal distribution is a continuous probability distribution with a family of two parameters.
Mean, Median, Mode
It is a descriptive summary of a data set. It can be defined by using some of the measures. The central tendencies do not provide information regarding individual data from the dataset. However, they give a summary of the data set. The central tendency or measure of central tendency is a central or typical value for a probability distribution.
Z-Scores
A z-score is a unit of measurement used in statistics to describe the position of a raw score in terms of its distance from the mean, measured with reference to standard deviation from the mean. Z-scores are useful in statistics because they allow comparison between two scores that belong to different normal distributions.
How do I get the variance ?
Step by step
Solved in 3 steps