Answer:
Pr(X >42) = Pr( Z > -2.344)
= Pr( Z< 2.344) = 0.9905
Step-by-step explanation:
The scenario presented can be modeled by a binomial model;
The probability of success is, p = 0.65
There are n = 80 independent trials
Let X denote the number of drivers that wear a seat belt, then we are to find the probability that X is greater than 42;
Pr(X > 42)
In this case we can use the normal approximation to the binomial model;
mu = n*p = 80(0.65) = 52
sigma^2 = n*p*(1-p) = 18.2
Pr(X >42) = Pr( Z > -2.344)
= Pr( Z< 2.344) = 0.9905
Ok so we can see for every 2 cups of medium coffee, the balance goes down 5.30$. So that means that for every coffee, her balance goes down 2.65$. Solving for the x-intercept means how many medium coffees can I get until my balance is 0. First, we have to find the y-int so it's easy. The slope is -2.65 because for every medium coffee, her balance goes down 2.65$. So we have y=-2.65x+b. Plugging in any point, I choose (4,14.40), we get 14.4 = -2.65 × 4 +b. Solving for b we get 25 for the y intercept, meaning the equation is y = -2.65x + 25 . To find the x intercept, we set y=0. So we have 0 = -2.65x+25. Solving for x we get approx. 9.4. We can't have decimals so we round down to 9. So the x int is ≈ 9.4 meaning we can only buy 9 coffee and have a little extra. But, if the problem said how many more coffees can she get, then here is how we do it. Since she already got 4 coffees, and the max is 9, we do 9-4 and we get 5, so she can buy 5 coffeed more.
• P is the principal amount, $3000.00.
• r is the interest rate, 6% per year, or in decimal form, 6/100=0.06.
• t is the time involved, 8 years time periods.
• So, t is 8 year time periods.
To find the simple interest, we multiply 3000 × 0.06 × 8 to get that:
The interest is: $1440.00
Use a system of equations
C+P=1132
3P=C
Substitute C in first equation as
3P+P=1132
Simplify
4P=1132
Solve
P=1132/4
P=283
NOW SOLVE FOR C SUBSTITUTING P VALUE IN FIRST EQUATION
C+283=1132
C=1132-283
C=849
Printer = 283$
Computer = 849$