Question

1. the table shows a restaurants cost per meal for each of the five types of meals the restaurant sells. if the mean cost per meal is $7.30, what is the cost per meal, in dollars, for grilled fish?

a. $5.40
b. $6.70
c. $7.90
d. $8.40

Explanation:

Step1: Recall the formula for the mean

The formula for the mean \(\bar{x}=\frac{\sum_{i = 1}^{n}x_{i}}{n}\). Here, \(n = 5\) (since there are 5 types of meals), and \(\bar{x}=7.30\). So, \(\sum_{i=1}^{5}x_{i}=n\times\bar{x}=5\times7.30 = 36.5\)

Step2: Set up the sum of the known and unknown costs

Let the cost of grilled - fish be \(x\). The sum of the known costs is \(7.30+8.20 + 7.00+8.60=31.1\). Then, using the sum formula from Step 1: \(31.1+x=36.5\)

Step3: Solve for \(x\)

Subtract \(31.1\) from both sides of the equation \(31.1+x=36.5\). So, \(x=36.5 - 31.1=5.4\)

Answer:

A. \(\$5.40\)