37.5 km is equal to 15 cm
We can solve this problem by referring to the standard
probability distribution tables for z.
We are required to find for the number of samples given the
proportion (P = 5% = 0.05) and confidence level of 95%. This would give a value
of z equivalent to:
z = 1.96
Since the problem states that it should be within the true
proportion then p = 0.5
Now we can find for the sample size using the formula:
n = (z^2) p q /E^2
where,
<span> p = 0.5</span>
q = 1 – p = 0.5
E = estimate of 5% = 0.05
Substituting:
n = (1.96^2) 0.5 * 0.5 / 0.05^2
n = 384.16
<span>Around 385students are required.</span>
Answer:
Step-by-step explanation:
Given
Points (-1,7) and (1,3)
Formula
m = (y2 = y1) / (x2 - x1)
y2 = 7
y1 = 3
x2 = - 1
x1 = 1
Solution
m = (7 - 3) / (-1 - 1)
m = 4 / - 2
m = - 2
Now use either one of the points to get b in y = mx + b
x = 1
y = 3
m = - 2
y = mx + b
3 = -2 (1) + b
3 = -2 + b
b = 3 + 2
b = 5
Equation: y = - 2x + 5
Second question.
y = -2 + 1
Think money. You have a dollar in your pocket, but you owe your mom 2 dollars. Where are you.
y = -2 + 1
y = - 1
0, 12, 36, 108
just plug n (1,2,3,4) into the equation and that’s your answer.
To find out if they are parallel we need to see if the gradient is the same, to do this we need to get y in terms of x:
assuming the first equation is x+y+7=0
y=-x-7
and
y=x-3
The gradient is the coefficient of x (the number infront of x)
For equation 1 the gradient is -1, and for number 2 it is 1, therefore they are not parallel.
However to check if they are perpendicular we need to see if their gradients multiply to equal -1.
-1*1=-1 therefore they are perpendicular
