Answer:
190 students
Step-by-step explanation:
Set up a proportion:
95/100 = x/200
Cross multiply:
100x = 19000
Simplify:
x = 190 students
The ratio of pop songs to rock songs you download is 5:4, and 40 are pop songs. You want to find out how many rock songs there are.
First, add the ratios together: 5+4=9. This means that 9 will be your denominator, so 5/9 songs are pop and 4/9 songs are rock.
Now you know that pop songs account for 5/9 of the songs, this means that 40 is 5/9 of the total songs.
To find out how much 4/9 is, you need to divide 40 by 5 to get 1/9 and times that number by 4 to get 4/9:
40÷5=8×4=32 songs are rock songs
Answer:
By the Central Limit Theorem, the mean is 78, the standard deviation is and the shape is approximately normal.
Step-by-step explanation:
Central Limit Theorem
The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean and standard deviation , the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean and standard deviation .
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
Mean of 78 and a standard deviation of 6
This means that
Samples of n:
This means that the standard deviation is:
What are the mean, standard deviation, and shape of the distribution of x-bar for n?
By the Central Limit Theorem, the mean is 78, the standard deviation is and the shape is approximately normal.
It's less than a whole number like 2/1 times 1/2 is 2/2 or 1