tucker counted the number of words per page in his new book. words per page 57 147 147 147 147 155 177 177…

tucker counted the number of words per page in his new book. words per page 57 147 147 147 147 155 177 177 177 177 x is the number of words that a randomly - chosen page has. what is the expected value of x? write your answer as a decimal.

tucker counted the number of words per page in his new book. words per page 57 147 147 147 147 155 177 177 177 177 x is the number of words that a randomly - chosen page has. what is the expected value of x? write your answer as a decimal.

Answer

Explanation:

Step1: Count the frequency of each value

The value 57 appears 1 time, 147 appears 4 times, 155 appears 1 time, 177 appears 4 times. The total number of data - points is $1 + 4+1 + 4=10$.

Step2: Use the expected - value formula

The expected - value formula for a discrete random variable $X$ is $E(X)=\sum_{i}x_ip_i$, where $x_i$ are the possible values of $X$ and $p_i$ are their corresponding probabilities. The probability of a value $x_i$ is $p_i=\frac{n_i}{N}$, where $n_i$ is the frequency of $x_i$ and $N$ is the total number of data - points. $E(X)=57\times\frac{1}{10}+147\times\frac{4}{10}+155\times\frac{1}{10}+177\times\frac{4}{10}$ $=\frac{57\times1 + 147\times4+155\times1 + 177\times4}{10}$ $=\frac{57+588 + 155+708}{10}$ $=\frac{1508}{10}=150.8$

Answer:

$150.8$