For the past three months grace used her cell phone for 43 minutes 62 minutes and 57 minutes how many minutes would you have to use her cell phone this month for the average usage over the four months to be 55 minutes

Grace should use her phone for 58 minutes to maintain an average of 55 minutes.

Step-by-step explanation:

Usage of first month = 43 minutes

Second month = 62 minutes

Third Minutes = 57 minutes

Let, the usage of fourth month =  k minutes

Mean of the data = 5 minutes

Now, Average of a Data =  

⇒

or, 55  x 4 = 162 + k

⇒    220 - 162  = k

or, k = 58 minutes

So, Grace should use her phone for 58 minutes to maintain an average of 55 minutes.

13.46

step-by-step explanation:

16.80 x .20 = 13.46