Answer:
CI = 21 ± 0.365
Step-by-step explanation:
The confidence interval is:
CI = x ± SE * CV
where x is the sample mean, SE is the standard error, and CV is the critical value (either t score or z score).
Here, x = 21.
The standard error for a sample mean is:
SE = σ / √n
SE = 3.2 / √510
SE = 0.142
The critical value is looked up in a table or found with a calculator. But first, we must find the alpha level and the critical probability.
α = 1 - 0.99 = 0.01
p* = 1 - (α/2) = 1 - (0.01/2) = 0.995
Using a calculator or a z-score table:
P(x<z) = 0.995
z = 2.576
Therefore:
CI = 21 ± 0.142 × 2.576
CI = 21 ± 0.365
Round as needed.
Answer:
OBAMA
Step-by-step explanation:
Answer:
450
Step-by-step explanation:
Multiply the length (30) by the width (15)
30x15=450
Answer:
So the expression in standard form will be 
Step-by-step explanation:
We have given expression 
We have to write this expression in standard form
For writing in standard form first we have to multiply the expression
So after multiplication number 
So the expression in standard form will be
