This is what you need i think
Answer:
Step-by-step explanation:
t(-7)= 3(-7)= -21
s(-21)= 2-(-21)= 2 + 21= 23
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.
If there is a graph or something that you can show me, I'd be more than happy to help you.
The formula for simple interest is <em>I</em> = <em>prt</em>, where <em>I</em> is the amount of interest, <em>p</em> is the principal borrowed, <em>r</em> is the interest rate written as a decimal number, and <em>t</em> is the amount of time in years. First we find the amount of interest. He borrowed $35000 but paid back $46375. That means he paid 46375-35000 = $11375 in interest. We can now substitute our information into our interest formula:
11375=35000(<em>r</em>)(5)
11375=35000(5)(<em>r</em>) ----- remember that multiplication is commutative
11375=175000<em>r</em>
Divide both sides by 175000 to cancel it:
11375/175000 = 175000<em>r</em>/175000
0.065 = <em>r</em>
To convert this to a percentage, we multiply by 100:
0.065(100) = 6.5%
