The perimeter of the shape is 30 add all the sides
1) subtract 2y in both sides: (7y-2y)-6=(2y-2y)+8 which is 5y-6=8
2) Add 6 to both sides: 5y(-6+6)=8+6 which is 5y=14
3) Divide 5 on both sides: 5y/5=14/5 which is y=14/5 or y=2.8 or y=2 4/5
60% of 20 quizzes = 60/100*20 quizzes = 12 quizzes
Amount of quizzes remaining = 50 quizzes - 20 quizzes = 30 quizzes
He passes 80% of those 30 quizzes, so
80/100 * 30 quizzes = 24 quizzes
So, he passed 12 quizzes from the initial bunch and 24 quizzes from the rest, which totals to 12 quizzes + 24 quizzes = 36 quizzes.
Then, you see that he passed 36 quizzes, out of the total 50 quizzes, so the ratio is 36 quizzes / 50 quizzes = 36/50, which when converted as a percentage is 36/50 * 100% = 72%.
Therefore, he passed 72% of the quizzes for the entire year.
Answer:
y is also doubled.
Step-by-step explanation:
Direct proportionality between and means that
or
,
which indicates a linear relationship between and because they are related by a constant.
Therefore, if x is doubled, then the new value of is
The new value of is 2 times the previous; therefore, is doubled as is doubled.
Part a)
The simple random sample of size n=36 is obtained from a population with
and
The sampling distribution of the sample means has a mean that is equal to mean of the population the sample has been drawn from.
Therefore the sampling distribution has a mean of
The standard error of the means becomes the standard deviation of the sampling distribution.
Part b) We want to find
We need to convert to z-score.
Part c)
We want to find
We convert to z-score and use the normal distribution table to find the corresponding area.
Part d)
We want to find :
We convert to z-scores and again use the standard normal distribution table.