Answer:
The number is 12
Step-by-step explanation:
4 times a number is 8 more than 40
Write the equation
4n=40+8
4n =48
Divide each side by 4 to isolate n
4n/4 = 48/4
n = 12
Answer:
The margin of error is 6.45.
Step-by-step explanation:
The complete question is:
As an early intervention effort, a school psychologist wants to estimate the average score on the Stanford-Binet Intelligence Scale for all students with a specific type of learning disorder using a simple random sample of 36 students with the disorder.
Determine the margin of error, of a 99% confidence interval for the mean IQ score of all students with the disorder. Assume that the standard deviation IQ score among the population of all students with the disorder is the same as the standard deviation of IQ score for the general population, σ = 15 points.
The (1 - <em>α</em>)% confidence interval for population mean <em>μ</em> is:

The margin of error for this interval is:

Given:
<em>n</em> = 36
σ = 15
(1 - <em>α</em>)% = 99%
Compute the critical value of <em>z</em> for 99% confidence level as follows:

*Use a <em>z</em>-table.
Compute the value of MOE as follows:



Thus, the margin of error is 6.45.
Let the number of red skittles be = x
Let the number of orange skittles be = y
Red skittles are 10 less than orange, this gives
x = y-10................(i)
Orange Skittles are twice the number of red skittles, this gives
y = 2x.............(ii)
Incorporating the value of y from second equation into first
x = 2x - 10
hence, x = 10
Now putting the value of x in equation second
y = 2x
y = 2*10
y = 20
Hence, the number of red skittles are 10 and the number of orange skittles are 20.