Answer:
d
Step-by-step explanation:
Answer:
The 80% confidence interval for the mean number of toys purchased each year is between 7.5 and 7.7 toys.
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 .
That is z with a pvalue of , so Z = 1.28.
Now, find the margin of error 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 sample mean subtracted by M. So it is 7.6 - 0.1 = 7.5
The upper end of the interval is the sample mean added to M. So it is 7.6 + 0.1 = 7.7
The 80% confidence interval for the mean number of toys purchased each year is between 7.5 and 7.7 toys.
Answer:
Step-by-step explanation:
Urn U1: 3 red and 2 yellow marbles, in total 5 marbles.
The probability to select red marble is
Urn U2: 3 red and 7 yellow marbles, in total 10 marbles.
The probability to select red marble is
Urn U1: 1 red and 4 yellow marbles, in total 5 marbles.
The probability to select red marble is
The probability to choose each urn is the same and is equal to
Thus, the probability that the marble is red is
you combine like terms first.
for example: 2x=2+5
add up the two plus 5 so that will give you seven then you're going to divide 2 by 7 so that you isolate the x and you'll get your answer.