Answer:
$20,000
Step-by-step explanation:
if he invests 20000 he will get 5% of that each year, 5% of 20000=1000 meaning he will have a 1000 yearly interest rate
Answer:
a

b

c
Option A is correct
Step-by-step explanation:
From the question we are told that
The sample size is n = 15
The probability of success is 
The number of success we are considering is r = 10
Now the probability of failure is mathematically evaluated as

substituting value


Now using the binomial distribution to find the probability of exactly 10 successes we have that
![P(X = r ) = [\left n } \atop {r}} \right. ] * p^r * q^{n- r}](https://tex.z-dn.net/?f=P%28X%20%3D%20%20r%20%29%20%3D%20%20%5B%5Cleft%20n%20%7D%20%5Catop%20%7Br%7D%7D%20%5Cright.%20%5D%20%2A%20p%5Er%20%2A%20%20q%5E%7Bn-%20r%7D)
substituting values
![P(X = 10 ) = [\left 15 } \atop {10}} \right. ] * p^{10}* q^{15- 10}](https://tex.z-dn.net/?f=P%28X%20%3D%20%2010%20%29%20%3D%20%20%5B%5Cleft%2015%20%7D%20%5Catop%20%7B10%7D%7D%20%5Cright.%20%5D%20%2A%20p%5E%7B10%7D%2A%20%20q%5E%7B15-%2010%7D)
Where
mean 15 combination 10 which is evaluated with a calculator to obtain
![[\left 15 } \atop {10}} \right. ] = 3003](https://tex.z-dn.net/?f=%5B%5Cleft%2015%20%7D%20%5Catop%20%7B10%7D%7D%20%5Cright.%20%5D%20%20%3D%203003)
So


Now using the normal distribution to approximate the probability of exactly 10 successes, we have that

Applying continuity correction

substituting values


Standardizing

The where
is the mean which is mathematically represented as

substituting values


The standard deviation is evaluated as

substituting values


Thus



From the normal distribution table we obtain the
as

And the 

There value can also be obtained from a probability of z calculator at (Calculator dot net website)
So


Looking at the calculated values for question a and b we see that the values are fairly different.
Answer:
2.85 × 10^7
Step-by-step explanation:
1.In scientific notation, the whole number before the decimal point shouln't be more than 10(exclude 10) or less than 1(include 1)
2.Count the digits after the decimal point to write the power.
Solution;
1. 2.85( 2 is not less than 1 as well as more than 10).
2.Since there are 7 digits after the decimal point, we should write the power 10^7.
3. Complete answer;
2.85 × 10^ 7
The given is f(x) = 620 · 7.8x
The standard equation for an exponential function is f(x) = Aoe^bx
where:
A is the initial amount
b is the growth factor which is constant
x is any real number
Therefore, the initial amount is 620 and the growth factor is 7.8