The "rule of 72" says that the doubling time in years is approximately 72 divided by the interest rate in percent. To make the money grow by a factor of 4 requires that it double twice, so will take twice as long as the period to double once.
2×72/11.3 ≈ 12.7 . . . . years
_____
The "rule of 72" is an approximation. The actual quadrupling time for this interest rate and compounding is about 12.6 years. (The actual product of doubling time and nominal interest rate is about 71.25.)
Answer:
0.0359
Step-by-step explanation:
Data provided:
mean values of three independent times are 15, 30, and 20 minutes
the standard deviations are 2, 1, and 1.6 minutes
Now,
New Mean = 15 + 30 + 25 = 65
Variance = ( standard deviation )²
or
Variance = 2² + 1² + 1.6² = 7.56
therefore,
Standard deviation = √variance
or
Standard deviation = 2.75
Thus,
Z-value = 
or
Z-value = - 1.81
from the Z-table
the Probability of Z ≤ -1.81 = 0.0359
Answer:
Step-by-step explanation:
Information provided
n=100 represent the random sample taken
X=21 represent the number of bags overfilled
estimated proportion of overfilled bags
is the value that we want to test
z would represent the statistic
Hypothesis
We need to conduct a hypothesis in order to test if the true proportion of overfilled bags is higher than 0.15.:
Null hypothesis:
Alternative hypothesis:
The statistic for this case is:
(1)
And replacing the info given we got:
Answer:
Step-by-step explanation:
$27.63 / 2 = $13.82
$13.82 * 0.20 = $2.76
$13.82 + $2.76 = $16.58
Answer:
a) 51.4
b) answer attached
c) 48.59% female
Step-by-step explanation:
a) Male driver = 100-48.6 = 51.4%
b) answer attached below
c) probability that out of 20-64 group a randomly selected sample is female
( 39.54 ÷ 81.36 ) x 100
= 48.59% chance of her being a female