Question

I just need the answer for question C.

Answer 1

To figure out the answer for Question C, we need to set up an equation, letting the unknown temperature recording for Saturday be represented by the variable x.  

We know that the mean can be found by adding up all of the numbers in a data set, and then dividing the sum by the amount of numbers we added together.

There are seven measurements (one for each day of the week.)

(56 + 58 + 54 + 59 + 51 + 48 + x) / 7 = 55 (the mean)

When simplified, you get 

326 + x / 7 = 55

To get rid of the denominator of 7 on the left side of the equation, we have to multiply the right side by 7. Thus, we get:

326 + x = 385

Now, we must subtract 326 from both sides to get the variable x alone.

x = 59

Therefore, the low temperature on Saturday was 59 degrees.

Answer 2

$\dfrac{56+58+54+59+51+48+x}{7}=55\\ \dfrac{326+x}{7}=55\\326+x=385\\ x=59$