Question

A college student realized that he was spending too much money on movies. For the remaining 5 months of the year his goal is to spend a mean of S10 a monthtowards movies, How much can he spend in December, taking into consideration that in the other 4 monthshe spent $35, 565,520, and $70, respectively Roundyour answer to two decimal places, if necessaryAnswerHow to enter your answerKeypadKeyboard Shortcuts

Answer 1

The student wants to spend a mean of X[bar]=$40 a month for 5 months.

She already spent $35, $65, $20, $70 in 4 months, and you need to calculate how much she has to spend in the 5th month to reach her goal.

The mean can be calculated as

$X\lbrack bar\rbrack=\frac{\Sigma x_i}{n}$

Where

Σxi is the sum of all observations, in this example, her monthly spending

n is the sample size, in this example the number of months

The information we have is then:

If X[bar] =$40, you can calculate the expenses for the fifth month as follows:

$\begin{gathered} X\lbrack bar\rbrack=\frac{x_1+x_2+x_3+x_4+x_5}{n} \\ 40=\frac{35+65+20+70+x}{5} \\ 40=\frac{190+x}{5} \end{gathered}$

Multiply both sides by 5

$\begin{gathered} 5\cdot40=5(\frac{190+x}{5}) \\ 200=190+x \\ x=200-190 \\ x=10 \end{gathered}$

She can spend $10 in December.