Answer:
And rounded up we have that n=3382
Step-by-step explanation:
Previous concepts
A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".
The margin of error is the range of values below and above the sample statistic in a confidence interval.
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
Solution to the problem
In order to find the critical value we need to take in count that we are finding the interval for a proportion, so on this case we need to use the z distribution. Since our interval is at 98% of confidence, our significance level would be given by and . And the critical value would be given by:
The margin of error for the proportion interval is given by this formula:
(a)
And on this case we have that and we are interested in order to find the value of n, if we solve n from equation (a) we got:
(b)
Since we don't have prior information for the estimated proportion we can assume . And replacing into equation (b) the values from part a we got:
And rounded up we have that n=3382
The estimated value is 900
Answer:
TV is 16 inches tall.
Step-by-step explanation:
Given Data:
Width of TV = w = 30 inches
Diagonal length of TV = d = 34 inches
To Find out:
height of TV = h = ?
Formula:
According to Pythagoras's theorem.
Solution:
h = 16 inches
Hence TV is 16 inches tall.
Answer:
it lies between 8 hours and 12 hours in a week
Step-by-step explanation:
Since in the question it is mentioned that the distribution consist of uni-modal, symmetric and bell shaped so here the empirical formual to be used for the mean and the standard deviation
Also the 68% would be fall within one standard deviation above and below the mean
Now
1 standard deviation below the mean is
= 10 - 2
= 8 hours
And, above the mean is
= 10 + 2
= 12 hours
Hence, it lies between 8 hours and 12 hours in a week