Given:
Total number of marbles in the bag = 150
There are 21 blue marbles for every 4 white marbles.
To find:
The number of blue marbles in the bag.
Solution:
Since, there are 21 blue marbles for every 4 white marbles, therefore the ratio of blue marble to white marbles is 21:4.
Let the number of blue marbles be 21x and white marbles be 4x.
Total number of marbles in the bag = 150
Divide both sides by 25.
Now,
Therefore, the number of blue marbles is 126.
Answer:
The 95% confidence interval for the mean is between 0.985g/cm² and 1.047 g/cm².
Step-by-step explanation:
We have that to find our level, that is the subtraction of 1 by the confidence interval divided by 2. So:
Now, we have to find z in the Ztable as such z has a pvalue of .
So it is z with a pvalue of , so
Now, find M as such
In which is the standard deviation of the population and n is the size of the sample.
The lower end of the interval is the mean subtracted by M. So it is 1.016 - 0.0310 = 0.985 g/cm²
The upper end of the interval is the mean added to M. So it is 1.016 + 0.0310 = 1.047 g/cm²
The 95% confidence interval for the mean is between 0.985g/cm² and 1.047 g/cm².