Answer:
a.0.8664
b. 0.23753
c. 0.15866
Step-by-step explanation:
The comptroller takes a random sample of 36 of the account balances and calculates the standard deviation to be N42.00. If the actual mean (1) of the account balances is N175.00, what is the probability that the sample mean would be between
a. N164.50 and N185.50?
b. greater than N180.00?
c. less than N168.00?
We solve the above question using z score formula
z = (x-μ)/σ/√n where
x is the raw score,
μ is the population mean = N175
σ is the population standard deviation = N42
n is random number of sample = 36
a. Between N164.50 and N185.50?
For x = N 164.50
z = 164.50 - 175/42 /√36
z = -1.5
Probability value from Z-Table:
P(x = 164.50) = 0.066807
For x = N185.50
z = 185.50 - 175/42 /√36
z =1.5
Probability value from Z-Table:
P(x=185.50) = 0.93319
Hence:
P(x = 185.50) - P(x =164.50)
= 0.93319 - 0.066807
= 0.866383
Approximately = 0.8664
b. greater than N180.00?
x > N 180
Hence:
z = 180 - 175/42 /√36
z = 5/42/6
z = 5/7
= 0.71429
Probability value from Z-Table:
P(x<180) = 0.76247
P(x>180) = 1 - P(x<180) = 0.23753
c. less than N168.00?
x < N168.
z = 168 - 175/42 /√36
z = -7/42/6
z = -7/7
z = -1
Probability value from Z-Table:
P(x<168) = 0.15866
Answer:
She should leave a total of $78.
Step-by-step explanation:
To find this, we first need to find the tip amount. We can do this by multiplying the total by the tip percentage.
$65 * 20% = $13
Now that we have that, we need to add it to the cost.
$65 + $13 = $78
Answer:
The answer is 1/3 or 0.33
Step-by-step explanation:
Let's consider the following ocurrences:
A: A person has a MasterCard
B: A person has an American Express
The data says:
P(A∩B) = 0.2
P(A without B) = 0.4
P(B without A) = 0.1
Then, P(A) = P(A∩B) +P(A without B) = 0.2+0.4 = 0.6
By conditional probability theory:
P (B/A) = P(A∩B) / P(A) = 0.2 / 0.6 = 1/3 = 0.33
Thus
P(B/A) = 1/3 = 0.33
Over time, compound interest at any rate will outperform simple interest. When the rates are nearly equal to start with, compound interest will be greater in very short order. Here, it takes less than 1 year for compound interest to give a larger account balance.
In 30 years, the simple interest will be
... I = P·r·t = 12,000·0.07·30 = 25,200
In 30 years, the compound interest will be
... I = P·(e^(rt) -1) = 12,000·(e^(.068·30) -1) ≈ 80,287.31
_____
6.8% compounded continuously results in more total interest
