Step-by-step explanation:
-3-24x-36>-111
-39-24x>-111
-24x>-111+39
-24x>-72 /x(-1)
24x<72
x<2.66
Given:
μ = 2 min, population mean
σ = 0.5 min, population standard deviation
We want to find P(x>3).
Calculate the z-score
z= (x-μ)/σ = (3-2)/0.5 = 2
From standard tables, obtain
P(x ≤ 3) = P(z ≤ 2) = 0.9772
Therefore
P(x > 3) = P(z > 2) = 1 - 0.9772 = 0.0228
Answer: 0.02275
0 X 13 = 0
1 X 13 = 13
2 X 13 = 26
3 X 13 = 39
4 X 13 = 52
5 X 13 = 65
6 X 13 = 78
7 X 13 = 91
8 X 13 = 104
9 X 13 = 117
10 X 13 = 130
11 X 13 = 143
12 X 13 = 156
13 X 13 = 169
14 X 13 = 182
15 X 13 = 195
16 X 13 = 208
17 X 13 = 221
18 X 13 = 234
19 X 13 = 247
<span>20 X 13 = 260</span>
Add up minutes
1stmonth+2ndmonth+3rdmonth=320+243+489=1052
how many 200's are there
6 of them (companies want money so they see, ok, you bought like 1 minute, we will charge you for the whole 200 minutes since you got in that zone)
6 times 25=150
cost is $150 (mom is not going to be happy, she spend like 3% of her waking hours takling on the phone)
