Answer:
609
Step-by-step explanation:
Standard deviation =
= $30
Margin of error = E = $2
Confidence level = 90%
Since the distribution is said to be normal, we will use z scores to solve this problem.
The z score for 90% confidence level = z = 1.645
Sample size= n = ?
The formula to calculate the margin of error is:

Using the values in above equation, we get:

This means, the minimum number of observations required is 609
Answer:
C; right answer on Khan Academy
Step-by-step explanation:
Answer:
x = - 9, x = 0, x = 7
Step-by-step explanation:
Given
x(x - 7)(x + 9) = 0 ← in standard form
Equate each factor to zero and solve for x
x = 0 ⇒ x = 0
x - 7 = 0 ⇒ x = 7
x + 9 = 0 ⇒ x = - 9
V= 3.14• 5^2•4
V= 3.14 •25•4
V= 78.5•4
V=314
Sorry I couldn’t give a more detailed explanation but here is the original equation for volume of a cylinder:
V=πr2h
Hope this helps comment below for more questions :)
Not counting negative numbers there are 337,675 numbers less than 337,676