Question

Pls help I’ll give you 35 points Sina's goal is to exercise a
mean of 45 minutes per
day for one week. She
exercised 35, 40, 37, 42,
45, and 50 minutes for six
days. How many minutes
must she exercise on the
seventh day in order to
reach her goal exactly?

Answer 1

Answer:

26 minutes

Step-by-step explanation:

Since the mean is the average of all the number, we need to reach a total of 315 minutes for the entire week.

$35+40+37+42+45+50=\\75+40+37+42+45+50=\\115+37+42+45+50=\\152+42+45+50=\\194+45+50=\\239+50=\\289$

Since 315 - 289 = 26, she needs to exercise for 26 minutes on the 7th day in order to reach her goal.

Answer 2

Answer:

26 minutes

Step-by-step explanation:

Let; x be the minutes exercised on the seventh day .

30 + 40 + 37 + 42 + 45 + 50 + x ÷ 6 = 45

244 + x ÷ 6 = 45

Now; the least common multiple is 6

So; multiplying 6 with both sides.

6 * 244 + x ÷ 6 = 45 *6

244 + x = 270

Making x the subject

x = 270 - 244

x = 26

Therefore Sina must exercise for 26 minutes on the seventh day in order to reach her goal exactly.

Note:

Mean is given by adding of numbers given divided by the number of numbers .

Example.

Find the mean of 2,4,3

so;we have 3 numbers

adding numbers = 2 + 4 + 3÷3 = 9÷3 = 3

therefore the mean is 3 .

So; with your question the mean is already given but left with one digit which is the 26 .Hence,you have to represent it by a variable and equate it to the mean given.

with change of subject and further calculation , you will get the result which is the 26 minutes