The mean ( average ) is given as 1200 hours.
The standard deviation is 200, sample size is 100.
Find the standard error:
√(200^2 / 100) = 20
Now calculate the confidence interval. For 95% the Z number is 1.96
Multiply Z by the standard error:
1.96 x 20 =39.2
Now find the range that the mean should be within:
1200 - 39.2 = 1160.8
1200 + 39.2 = 1239.2
The samples should be between 1160.8 and 1239.2 for a 95% confidence interval.
Since the average was 1050, which is below 1160.8 the bulbs are not in compliance.
Answer:
148 books
Step-by-step explanation:
Let's take the difference between the old and new (70 - 60) to get 10 and then divide this by the old (70) amount...10/70 = .142857 convert to a percent by moving the decimal 2 spaces to the right... 14.29 %
Answer:
D 13
Step-by-step explanation:
To find out how many floors the building has, we take the height of the building and divide by the size of each floor
floors = 185.9 ft / 14.3ft per floor
= 13 floors
Answer:
Graph C
Step-by-step explanation:
Hi there!
The given linear equations are organized in slope-intercept form: 
where <em>m</em> is the slope of the line and <em>b</em> is the y-intercept, or the value of y when the line crosses the y-axis.
y = 2x + 4
Here, the <em>b</em> value is 4. Therefore, the y-intercept of this line is 4.
y = -3x - 2
Here, the <em>b</em> value is -2. Therefore, the y-intercept of this line is -2.
To identify the graph that models these equations, we just have to look for the graph where the lines cross the y-axis at 4 and -2.
The only graph that does this is graph C.
I hope this helps!
