Q1 a) Kamahi invests some money which earns compound interest every year. His investment
2 answers:
Without any more information, it sounds like interest is compounded continuously, in which case the value of the investment <em>A</em> is given by
where <em>P</em> is the principal investment, <em>r</em> is the interest rate, and <em>t</em> is the number of years.
At the end of the second year (<em>t</em> = 2), the value is <em>A</em> = 60,500, and after the fourth year (<em>t</em> = 4), the value is <em>A</em> = 73,205. So solve the system
for <em>r</em>. You can eliminate <em>P</em> by dividing
Take the logarithm (log here means natural log) of both sides to get
2<em>r</em> = log(121/100)
<em>r</em> = 1/2 log(121/100)
<em>r</em> ≈ 0.0953
So the interest rate is about 9.53%.
You might be interested in
Answer:
If the observed sample mean is greater than 17.07 minutes, then we would reject the null hypothesis.
Step-by-step explanation:
We are given the following in the question:
Population mean, μ = 15 minutes
Sample size, n = 10
Alpha, α = 0.05
Population standard deviation, σ = 4 minutes
First, we design the null and the alternate hypothesis
Since the population standard deviation is given, we use one-tailed z test to perform this hypothesis.
Formula:
Now,
Thus, we would reject the null hypothesis if the z-statistic is greater than this critical value.
Thus, we can write:
Thus, the decision rule would be if the observed sample mean is greater than 17.07 minutes, then we would reject the null hypothesis.