Answer:
Step-by-step explanation:
Mean weigth is 3.8
standard deviation 15 =0.5
sd2 =15*(sd₁₅ )²
sd=(15*0.25)^0.5
sd=1.94
z=(3.8-4)/((0.5)/15^0.5)
z=-1.55
p=0.060571
0.060571>.05
true mean weight is less than 4 ounces
test statistic= (sample mean-mean)/((sd of sample)/n^0.5)
test statistic=(3.8-4)/((0.5)/15^0.5)
test statistic=-1.55
Plug x = 4 into the equation and solve for y
3(4) - y = 4
y = 8
The point is (4, 8)
J=2l
j+l=240
sub 2l for j
2l+l=240
3l=240
divide both sides by 3
l=80
sub
j=2l
j=2(80)
j=160
jane does 160 envelopes