Chapter 2: Problem 7
Suppose a coin having probability \(0.7\) of coming up heads is tossed three times. Let \(X\) denote the number of heads that appear in the three tosses. Determine the probability mass function of \(X\).
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Chapter 2: Problem 7
Suppose a coin having probability \(0.7\) of coming up heads is tossed three times. Let \(X\) denote the number of heads that appear in the three tosses. Determine the probability mass function of \(X\).
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Suppose three fair dice are rolled. What is the probability that at most one six appears?
Let \(c\) be a constant. Show that (i) \(\operatorname{Var}(c X)=c^{2} \operatorname{Var}(X) .\) (ii) \(\operatorname{Var}(c+X)=\operatorname{Var}(X)\).
An individual claims to have extrasensory perception (ESP). As a test, a fair coin is flipped ten times, and he is asked to predict in advance the outcome. Our individual gets seven out of ten correct. What is the probability he would have done at least this well if he had no ESP? (Explain why the relevant probability is \(P[X \geq 7\\}\) and not \(P(X=7) .\) )
The density of \(X\) is given by $$ f(x)=\left\\{\begin{array}{ll} 10 / x^{2}, & \text { for } x>10 \\ 0, & \text { for } x \leq 10 \end{array}\right. $$ What is the distribution of \(X ?\) Find \(P[X>20]\).
If \(X\) is normally distributed with mean 1 and variance 4 , use the tables to
find \(P \mid 2
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