Answer:
136
Step-by-step explanation:
theory: sum of opposite interior angles is equal to exterior angle
do oh understand?
Answer:
We need a sample size of at least 383.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of
, and a confidence level of
, we have the following confidence interval of proportions.

In which
z is the zscore that has a pvalue of
.
The margin of error is:

85% confidence level
So
, z is the value of Z that has a pvalue of
, so
.
How large a sample would be required in order to estimate the fraction of tenth graders reading at or below the eighth grade level at the 85% confidence level with an error of at most 0.03
We need a sample size of at least n.
n is found with 
Then






Rounding up
We need a sample size of at least 383.
20 mins: it says the answer in the graph
Answer:
two real roots
Step-by-step explanation:
y = -2x^2 + 9x - 7
This is in the form
ax^2 +bx+c
a = -2 b = 9 c = -7
The discriminant is
b^2 -4ac
(9)^2 - 4(-2) (-7)
81 - 56
25
Since the discriminant is greater than zero, there are two real roots