Answer:
Step-by-step explanation:
We would apply the formula for exponential decay which is expressed as
A = P(1 - r/n)^ nt
Where
A represents the value after t years.
n represents the period for which the decrease in value is calculated
t represents the number of years.
P represents the value population.
r represents rate of decrease.
From the information given,
P = 23000
r = 8% = 8/100 = 0.08
n = 1
Therefore, the exponential decay function described in this situation is
A = 23000(1 - 0.08/n)1)^ 1 × t
A = 23000(0.92)^t
If A = 15000, then
15000 = 23000(0.92)^t
0.92^t = 15000/23000 = 0.6522
Taking log of both sides to base 10
Log 0.92^t = log 0.6522
tlog 0.92 = log 0.6522
- 0.036t = - 0.1856
t = - 0.1856/- 0.036
t = 5 years to the nearest year
The first inequality has solution
4p > -8 . . . . . . subtract 1
p > -2 . . . . . . . divide by 4
This is graphed as an open dot at -2, with shading to the right.
Neither inequality symbol includes "or equal to", so both dots are open dots. The appropriate choice is the first one:
a number line with open circles at negative 2 and 5 with shading in between
Answer:
95% of the text messages have length between 23 units and 47 units.
Step-by-step explanation:
We are given the following in the question:
The lengths of text messages are normally distributed.
95% confidence interval:
(23,47)
Thus, we could interpret the confidence interval as:
About 95% of the text messages have length between 23 units and 47 units.
By Empirical rule for a normally distributed data, about 95% of data lies within 2 standard deviations of mean , thus we can write:
Thus, the mean length of text messages is 23 units and standard deviation is 6 units.
