A new plasma-screen television has a purchase price of $9460 if the sales tax on this purchase is $756.80 find the sales taz rat
1 answer:
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Answer:
--- Standard deviation
Step-by-step explanation:
Given
See attachment for graph
Solving (a): Explain how the standard deviation is calculated.
<u>Start by calculating the mean</u>
To do this, we divide the sum of the products of grade and number of students by the total number of students;
i.e.
So, we have:
Next, calculate the variance using the following formula:
i.e subtract the mean from each dataset; take the squares; add up the squares; then divide the sum by the number of dataset
So, we have:
Lastly, take the square root of the variance to get the standard deviation
--- approximated
<em>Hence, the standard deviation is approximately 11.28</em>
Considering the calculated mean (i.e. 82.76), the standard deviation (i.e. 11.28) is small and this means that the grade of the students are close to the average grade.
Answer:
Step-by-step explanation:
9) PQR Is an isosceles triangle
=> ∠PRQ = (180° - x)/2
PRS is an isosceles right triangle
=> ∠PRS = 45°
Have: ∠PRS + ∠PRQ = 115°
=>
=> 180 - x = (115 - 45).2 = 140
<=> x = 180 - 140 = 40
10) ABD is an isosceles right triangle => ∠ABD = 45°
BCD is an equilateral triangle => ∠CBD = 60°
have: x = ∠ABD + ∠CBD = 45° + 60° = 105°
11) have: x = y (2)
PQT is an isosceles triangle => ∠PQT = 180 - 70.2 = 40
QTS is an isosceles triangle => ∠TQS = 180 -2x
QRS is an isosceles triangle => ∠RSQ = y
have: 40 + 180 - 2x + y = 180 => 2x - y = 40 (1)
(1)(2) =>
=> x + y = 80
12) EFJ Is an equilateral triangle => ∠FJE = 60
∠FJE is the outer angle of the triangle FHJ but FHJ is an isosceles triangle
=> 60 = 2.∠JHF => ∠JHF = 30°
∠JHF is the outer angle of the triangle FHG
=> 30° = 2x
<=> x = 15°