Answer:
At least 547 records need to be studied.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of
, and a confidence interval
, we have the following confidence interval of proportions.

In which
Z is the zscore that has a pvalue of
.
And the margin of error is:

95% confidence interval
So
, z is the value of Z that has a pvalue of
, so
.
In this problem, we have that:






At least 547 records need to be studied.
A.50*9.8
B.50*1.6
C.45.359237
D.45.3*1.6
Remember that the area of a square is just one of its sides squared.

where

is the area of the square

is one of the sides of the square
Unit square is a square whose sides have length 1, so lets use our formula to find the volume of one unit square:



We now know that each one of the squares has area 1 unit squared. Since there are 28 unit square in our figure, we are going to multiply the area of a unit square by 28 to find the area of our figure:
Area of the figure=

units squared
We can conclude that the area of the figure is 28 units squared.
The average speed of his trip is = 12 mile/ hour
The total distance covered by the driver = 240 miles
The rate at which he traveled = 12 miles per hour
Therefore, the time he used to cover his distance
= 240/12
= 20 hrs
But average speed = distance/ time
= 240/ 20
= 12 miles/ hour
Therefore, the average speed of his trip is = 12 mile/ hour
Learn more here:
brainly.com/question/11753352
Answer:
3
Step-by-step explanation:
i would say 3 different ways because 4 x 3 = 12
Hope this helps!