We are looking for the probability :

Transform the law to standard normal like this:

The above formula is equivalent to this one:

From normal law table, we read the value of

.

Solving the above equation for the score n:


, it is the score we are looking for.
The salads in total are $9.50
The waters in total are $3.30
together the total cost is $12.80
First, convert the 15% to an actual number that can be used in a calculation. For percents, this is always done by simply dividing the percent (in this case 15%) by 100%. So, the conversational term "15%" becomes 15% / 100% = 0.15 in terms of a real mathematical number.
Second, you need to find out what 15% of your $12.80 meal cost is. This is always done by multiplying 0.15 by $12.80, or
0.15 x $12.80=$1.92.
So, the amount of tip you are going to leave is $1.92.
This makes the total cost of your meal (to write on your charge slip or other payment)
<span>$12.80 + $1.92 = $14.72.</span>
Answer:
70 times
you didn't attach a picture so i can't help with the other part
Step-by-step explanation:
Divide 90 by 1.3 and you will get your answer.
Do it yourself! just follow instructions!
<3