Answer: option A
Step-by-step explanation:
Sample proportion (p') = 1600/2000 = 0.8
Sample size (n) = 2000
q' = 1 - p' = 1 - 0.8 = 0.2
To construct a 95% confidence level for population proportion, we use the formulae below.
p = p' + Zα/2 × s/√n..... For the upper limit
p = p' - Zα/2 × s/√n..... For the lower limit
Where s is the sample standard deviation and is given below as
s = √ p' (1-p')
s = √ 0.8 × 0.2
s = √ 0.16
s = 0.4
Even though we are making use of our sample standard deviation, the critical value use is that of a z test and that's because the sample size is greater than 30 ( n = 2000.)
Hence the value for critical value Zα/2 is 1.96.
By substituting the parameters, we have that
For lower limit
p = 0.8 - 1.96× 0.4/√2000
p = 0.8 - 1.96 ( 0.0089)
p = 0.8 - 0.018
p = 0.782 = 78.2%
For upper limit
p = 0.8 + 1.96× 0.4/√2000
p = 0.8 + 1.96 ( 0.0089)
p = 0.8 + 0.018
p = 0.818= 81.8%
Hence the 95% confidence interval for proportion is between 78.2% and 81.8%
That’s what I need 25!:$:63737
Answer:
y incpy would be 1/5
Step-by-step explanation:
Answer:
40 square units
Step-by-step explanation:
Its a Right triangle, so you can use either of the legs of the right angle as the base and the height interchangeably.
Flip it over in your mind Area of a triangle is Hald of the base times height.
10 ×8 = 80 Divide by 2
80/2 = 40 units²
The slope of AC is -0.4
Proof:
In triangles ABC and DBE,
∠DBE is common to both triangles.
AB = 2DB (D is the midpoint of the interval AB)
Also, BC = 2BE (E is the midpoint of the interval BC)
Thus triangles ABC and DBE are similar in the ratio 2:1
Since, they are similar, ∠BDE must equal ∠BAC (corresponding angles in similar triangles)
If ∠BDE = ∠BAC, DE must be parallel to AC (corresponding angles are equal along parallel lines)
Thus, the slope of AC = the slope of DE
Thus, the slope of AC is -0.4