Answer:
The margin of error for the 99% confidence level for this sample is ±2.23.
None of the given figures is close to the answer:
E. None of the above
Step-by-step explanation:
margin of error (ME) around the mean can be calculated using the formula
ME=
where
- z is the corresponding statistic of the 99% confidence level (2.576)
- s is the population IQ standard deviation (15)
- N is the sample size (300)
Using these numbers we get:
ME=
≈ 2.23
Solve the following system using elimination:
{7 x + 2 y = -19 | (equation 1)
{2 y - x = 21 | (equation 2)
Add 1/7 × (equation 1) to equation 2:
{7 x + 2 y = -19 | (equation 1)
{0 x+(16 y)/7 = 128/7 | (equation 2)
Multiply equation 2 by 7/16:
{7 x + 2 y = -19 | (equation 1)
{0 x+y = 8 | (equation 2)
Subtract 2 × (equation 2) from equation 1:
{7 x+0 y = -35 | (equation 1)
{0 x+y = 8 | (equation 2)
Divide equation 1 by 7:
{x+0 y = -5 | (equation 1)
{0 x+y = 8 | (equation 2)
Collect results:
Answer: {x = -5, y = 8
Answer:
The number of skateboard company sell during the month of August = 55
Step-by-step explanation:
We have given,
Profit function for Bob, P = x²+ 10x - 12
Bob's profit during August month is $3,563
That means, P = $3,563
We can use the profit formula given for Bob's profit:
P = x² + 10x - 12
Plug P =$3,563 in above formula.
i.e 3,563 = x² + 10x - 12
or 0 = x² + 10x -12 - 3,563
or 0 = x² + 10x - 3575
or x = 55, -65
Since number of skate boards can not be negative.
So we consider x= 55
Hence the number of skateboard company sell during the month of August = 55.
