Answer:
129
Step-by-step explanation:
Considering the survey to be representative, you can simply multiply the share of students <em>p</em> preferring “Track & Field” with the whole school population at the same time to estimate the number of such students in the whole school.
First we need to find the relative share <em>p</em> of such answers in the study by dividing it by the sum of answers, assuming that the table is complete for that random sample:
<em>p</em> = 4/(8 + 5 + 4) = 4/17
Then for the whole school we get 550 <em>p</em> ≈ 129.4
The answer is letteer C. You just have to multiply 9 and pi
First term ,a=4 , common difference =4-7=-3, n =50
sum of first 50terms= (50/2)[2×4+(50-1)(-3)]
=25×[8+49]×-3
=25×57×-3
=25× -171
= -42925
derivation of the formula for the sum of n terms
Progression, S
S=a1+a2+a3+a4+...+an
S=a1+(a1+d)+(a1+2d)+(a1+3d)+...+[a1+(n−1)d] → Equation (1)
S=an+an−1+an−2+an−3+...+a1
S=an+(an−d)+(an−2d)+(an−3d)+...+[an−(n−1)d] → Equation (2)
Add Equations (1) and (2)
2S=(a1+an)+(a1+an)+(a1+an)+(a1+an)+...+(a1+an)
2S=n(a1+an)
S=n/2(a1+an)
Substitute an = a1 + (n - 1)d to the above equation, we have
S=n/2{a1+[a1+(n−1)d]}
S=n/2[2a1+(n−1)d]
1a. 5/10 can be simplified to 1/2. (5 divided by 5 is one, 10 divided by 5 is 2.)
1b. 9/12 can be simplified to 3/4. (9 divided by 3 is 3, 12 divided by 3 is 4.)
1c. 12/18 can be simplified to 2/3. (12 divided by 6 is 2, 18 divided by 6 is 3.)
1d. 9/24 can be simplified to 3/8. (9 divided by 3 is 3, 24 divided by 3 is 8.)
1e. 27/90 can be simplified to 3/10. (27 divided by 9 is 3, 90 divided by 9 is 10.)
1f. 40/48 can be simplified to 5/6. (40 divided by 8 is 5, 48 divided by 8 is 6.)
