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%
T=90 because:
first, solve for other variables
(131)2+y*2=360 vertical angles are equal
y= 49, then solve for x,
x=180-73-42
x= 65
another side is 66 in x triangle.
then find the vertical angle between the z and the t triangle,
73+66+t triangle side= 180
t triangle side =41
49+41+t=180
t=90
Answer:
A. 1 You are rounding down so the 1.2 is rounded to 1.
Step-by-step explanation:
The fractions of the class is 1/4 because 1/4+1/5=2/5 and 2/5 of the class is in band.
Answer:
D
Step-by-step explanation:
10 + 24 + 26
60 = tri