Answer:
Lizzy's recipe is not a proportional relationship with the brownie recipe because of the difference in ratio.
Step-by-step explanation:
Brownie recipe:
Cocoa powder = 3 parts
Flour = 2 parts
Ratio of cocoa powder to flour = 3 : 2
Lizzy's recipe:
Cocoa powder = 1 cup
Flour = 1 cup
Ratio of cocoa powder to flour = 1 : 1
To solve this problem, we use the formula:
z = (x – u) / s
where z is the z score value which can be obtained from
the tables, x is the sample value, u is the mean = 6.3 min, and s is the std
dev = 2.2 min
at P value = 0.90, the z = 1.28, finding for x:
x = z s + u
x = 1.28 * 2.2 + 6.3
x = 9.116
at P value = 1.0, the z = 3.49, finding for x:
x = z s + u
x = 3.49 * 2.2 + 6.3
x = 13.978 ~ 14
Therefore the longest 10% calls last about 9.1 minutes to
14 minutes
A) 4a+3w
b) 2b+h
c) 3(w+h)
d) (4a+3w)(2b+h) - 3(w+h)
just expand brackets for d and simplify