Answer:
The river is 3.15 feet deep.
Step-by-step explanation:
First let's recognize what we need to find: the depth of the river
We know last year the river was 4.2 feet deep, but it dropped 25%. This means we also need to find how much it dropped. To find this, we need to know what 25% of 4.2 is. Write an equation for this.
y = 25% of 4.2
y = 0.25 • 4.2
y = 1.05
This means that the river dropped 1.05 feet. To know its depth now, we need to subtract 1.05 from 4.2. Write an equation for this.
d = 4.2 - 1.05
d = 3.15
The river is 3.15 feet deep.
Hope this helps!
Answer:
-4 and 4
Step-by-step explanation:
An absolute value sign makes an answer positive regardless
30 = 60% of x
x being our variable, we need to figure out what x equals. Use the formula I put in the attachment. Multiply 30 by 60, and then divide the product by 100. That will give you the answer :)
We can get two different equations from this:
3x = 18
and
3x = -18
So:
x = 6, x = -6
x = {6, -6}
let n be the number of times letter be found (1800), p be the success rate (0.068), and q be the failure rate (1 - 0.068 = 0.932)
mean = np = 1800 x 0.068 = 122.4
standard deviation = √(npq) = √(1800 x 0.068 x 0.932) = 10.6807414
