After 5 tests, her average was 88. To have a seven-test average of 90, the total must be:

Her average after 5 tests was 88. Her total score on the 5 tests is:

Subtract:

Find the average by dividing by 2:

Her average must be 95
Rounded to the nearest cent, the answer is 1.19
To make the inequality, we will use the ≥ sign to determine how many more tickets we will need. Before we write the inequality, let's see how much money was already made by the present tickets. 70 x 9.50 = $665.
We can write the inequality as $665 + $9.50t ≥ $1000 where t is the number of tickets sold. Now we can solve
$665 + $9.50t ≥ $1000, subtract 665
$9.50t ≥ $335. Now isolate the t by divide 9.50 to both sides
t ≥ 35.26 which we can round up to 36 because you cant sell 35.26 tickets.
So you need at least 36 more tickets to earn at least $1000