Answer:
Step-by-step explanation:
Here, According to the question, The population of the world is 4 billion (approx).
Again According to the question, The world's population has grown at an average rate of 1.9 percent per year since 1945.
Therefore, after 1975 the growth rate will remains same.
Thus, the population of the world after t years,
(By the formula
)
⇒
Where 1.019 is the growth rate and 4 billion is the initial population.
Answer:
The 95% confidence interval for the population mean rating is (5.73, 6.95).
Step-by-step explanation:
We start by calculating the mean and standard deviation of the sample:
We have to calculate a 95% confidence interval for the mean.
The population standard deviation is not known, so we have to estimate it from the sample standard deviation and use a t-students distribution to calculate the critical value.
The sample mean is M=6.34.
The sample size is N=50.
When σ is not known, s divided by the square root of N is used as an estimate of σM:
The degrees of freedom for this sample size are:
The t-value for a 95% confidence interval and 49 degrees of freedom is t=2.01.
The margin of error (MOE) can be calculated as:
Then, the lower and upper bounds of the confidence interval are:
The 95% confidence interval for the mean is (5.73, 6.95).
