Answer:
the answer 9 - 16 is 13 it is a positive
Answer:
Choice D. 15.2%
Step-by-step explanation:
We have a normal...
mean u = 48
standard deviation s = 2
We want P(43 < X < 46)
We standardize.
Consider P(43 < X) = P( (43 - 48)/2 < Z) = P(-2.5 < Z)
P( X < 46) = P( Z < (46 - 48)/2 ) = P(Z < -1)
We want P( -2.5 < Z < -1)
Look at Z-scores.
P( Z < -2.5) = 0.0062
P(Z < -1) = 0.1587
so P(-2.5 < Z < -1) = P(Z < -1) - P(Z < -2.5) = 0.1587 - 0.0062 = 0.1525 = 15.2%
about
1/2 of 2 is 1 .
1/2 of 3 is (1 and 1/2).
1/2 of 4 is 2 .
We can write two equations for this. x = each minute of calls
Plan A = .1x + 16
Plan B = .14x
Make the two equations equal each other, so we can find when they are the same.
.1x + 16 = .14x
Subtract .1x from both sides
16 = 0.04x
Divide by 0.04 to get x by itself
400 = x.
Earlier, we set x as each minute of calls. This means that after 400 calls, Plan A and Plan B will cost the same.
To find the cost, substitute 400 into both equations by themselves.
Plan A cost = .1x + 16
Plan A cost = .1(400) + 16
Plan A cost = 40 + 16
Plan A cost = $56
Plan B cost = .14x
Plan B cost = .14(400)
Plan B cost = $56
Final answer: After 400 calls, Plan A and Plan B will both cost $56.
