Answer:
The 90% confidence interval to estimate the average difference in scores between the two courses is (-1.088, 20.252).
Step-by-step explanation:
We have the standard deviation for the differences, which means that the t-distribution is used to solve this question.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 8 - 1 = 7
90% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 7 degrees of freedom(y-axis) and a confidence level of 
. So we have T = 1.8946
The margin of error is:
In which s is the standard deviation of the sample and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 9.582 - 10.67 = -1.088
The upper end of the interval is the sample mean added to M. So it is 9.582 + 10.67 = 20.252
The 90% confidence interval to estimate the average difference in scores between the two courses is (-1.088, 20.252).
Answer:
Step-by-step explanation:
%profit = selling price - cost price/cost price * 100
If Mr. Wayne marks up every item with a profit of 25% and x be his cost for a calculator, the expression for the selling price can be gotten by substituting the parameters into the formula;
25 = sp-cp/cp * 100
25/100 = sp-x/x
0.25 = sp-x/x
cross multiply
0.25x = sp-x
add x to both sides
0.25x+x = sp-x+x
1.25x = sp
selling price = 1.25x
<em>Hence an expression for the selling price of the calculator is 1.25x</em>
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b) If Mr wayne paid $25, the selling price is derived by substituing x = $25 into the expression in (a)
selling price = 1.25x
selling price = 1.25($25)
selling price = $31.25
c) If the selling price is $86, to get the cost of the calculator, substitute the selling price into the expression in (a)
selling price = 1.25x
$86= 1.25x
x is the cost price of the calculator
divide both sides by 1.25
$86/1.25= 1.25x/1.25
x = $68.8
<em>Hence Wayne paid $68.8 for a calculator that he sells for $86.</em>
Answer:
I couldn't understand question paper plz can u give question with photo too.
Answer:
2/3 + 3/4 = 1 52/125. That plus 3 is 4 / 52/125. Sorry if this isn't the right answer.
