Answer:
Step-by-step explanation:
9 * -9 * -1 =
-81 * -1 =
81 <===
In multiplying (or dividing), if the signs are the same, the result is positive
if the signs are different, the result is negative
these rules do not apply to addition or subtraction
Answer is: 77575744.84403361
Step-by-step explanation:
Given precision is a standard deviation of s=1.8, n=12, target precision is a standard deviation of σ=1.2
The test hypothesis is
H_o:σ <=1.2
Ha:σ > 1.2
The test statistic is
chi square = 
=
=24.75
Given a=0.01, the critical value is chi square(with a=0.01, d_f=n-1=11)= 3.05 (check chi square table)
Since 24.75 > 3.05, we reject H_o.
So, we can conclude that her standard deviation is greater than the target.
the amount they paid includes the price of the two smoothies and tip
since the friends are splitting the bill in 2, then each friend pays only half the amount
each friend pays $ 3.60 each
so the total amount they both paid is 3.60 x 2 = $ 7.20
the cost of one smoothie - $3
therefore the cost of the 2 smoothies - 3 x 2 = $ 6
so they paid 7.20 but the bill was only 6 dollars
so the difference in the 2 amounts is the value of the tip they left
tip = 7.20 - 6 = 1.20
so the percentage of the tip is - tip amount / value of the bill x 100 %
percentage = 1.20 / 6.0 x 100 % = 20 %
they left 20 % of the bill as a tip
