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3. (a) (0) A uniform probability density function (rectangular distribution) describes the probability of a voltage occurring. The height of this function is 0.01.5 V is the lowest voltage covered by this function (x1). Determine the highest voltage covered by this function (x2), and briefly outline how this function is used for probability calculations. [6 Marks] (ii) A normal distribution in x has a mean of 0.5 and a standard deviation 1.5. Determine the probability that x will be less than or equal to 06. Use the following two methods to calculate this probability, Method 1. using a cumulative probability distribution function PCDF and erf tables, Method 2. converting the data to the variable z and using standard normal distribution tables. [10 Marks] (b) (0) A data source uses four symbols. X_X2X3, and X4 with probabilities of occurrence 0.1, 0.1, 0.1 and 0.7 respectively. Calculate the entropy of this source. (5 marks) (ii) An amplitude shift keying (ASK) method uses rectangular pulses for the data, where the pulse width is 4 us and the amplitude 1. . Write down an expression that describes the frequency content of a single pulse and determine the frequency where the amplitude first equals zero. Briefly explain how this expression can be utilised in communications. (5 marks)