There could be five in each class.
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%
Answer:
Step-by-step explanation:
The average rate of change is the change in the number of visitors divided by the change in the number of months.
1. Change in number of visitors
Change in visitors = 182 -125 = 57 visitors
2. Change in number of weeks
Change in time = 5 - 2 = 3 months
3. Average rate of change
Answer:
Step-by-step explanation:9
(x²+4)(x²+4) =x^4+8x²+16
B. x4 + 8x2 + 16