Answer:
Step-by-step explanation:
Steps
find the Least Common Multiple of the denominators (which is called the Least Common Denominator).
Change each fraction (using equivalent fractions) to make their denominators the same as the least common denominator.
Then add (or subtract) the fractions, as we wish!
your denominators stay the same so its 20
Answer:
<u>4 hours</u>
Step-by-step explanation:
Equations :
Larry : <u>y = 20x + 90</u>
Barry : <u>y = 30x + 50</u>
Equate both to find the number of hours at which they both charge the same :
- 20x + 90 = 30x + 50
- 30x - 20x = 90 - 50
- 10x = 40
- x = <u>4 hours</u>
<u>Supposing 60 out of 100 scores are passing scores</u>, the 95% confidence interval for the proportion of all scores that are passing is (0.5, 0.7).
- The lower limit is 0.5.
- The upper limit is 0.7.
In a sample with a number n of people surveyed with a probability of a success of
, and a confidence level of
, we have the following confidence interval of proportions.
In which
z is the z-score that has a p-value of
.
60 out of 100 scores are passing scores, hence 
95% confidence level
So
, z is the value of Z that has a p-value of
, so
.
The lower limit of this interval is:
The upper limit of this interval is:
The 95% confidence interval for the proportion of all scores that are passing is (0.5, 0.7).
- The lower limit is 0.5.
- The upper limit is 0.7.
A similar problem is given at brainly.com/question/16807970