Answer:
0.6604
Step-by-step explanation:
Given that a market research firm knows from historical data that telephone surveys have a 36% response rate.
Sample size of random sample = 280
We know for samples randomly drawn of large size sample proportion follows a normal distribution with mean= sample proportin and std error
= 
Substitute p = 0.36 and q = 1-0.36= 0.64
p follows N with mean = 0.36 and std dev = 
Using normal distribution values we can find\

Answer:
(2, 3).
Step-by-step explanation:
3x+2y=12
6x+3y=21 Multiply the first equation by 3 and the second by 2:
9x + 6y = 36
12x + 6y = 42 Subtract:
-3x = -6
x = -6/-3 = 2.
Plug x = 2 into the first equation:
3(2) + 2y = 12
2y = 12 - 3(2)
2y = 6
y = 3.
Answer:
.69
Step-by-step explanation:
For plan A it will only take five minutes to amount to $20.50
Plan B will need 30 min to cost the same as plan A $20.50