What are you looking for?? Area? Perimeter?
Answer:
95% z-confidence interval for the proportion of all children enrolled in kindergarten who attended preschool is between a lower limit of 0.528 and an upper limit of 0.772.
Step-by-step explanation:
Confidence interval = p + or - zsqrt[p(1-p) ÷ n]
p is sample proportion = 39/60 = 0.65
n is the number of children sampled = 60
Confidence level (C) = 95% = 0.95
Significance level = 1 - C = 1 - 0.95 = 0.05
Divide significance level by 2 to obtain critical value (z)
0.05/2 = 0.025 = 2.5%
z at 2.5% significance level = 1.96
zsqrt[p(1-p) ÷ n] = 1.96sqrt[0.65(1-0.65) ÷ 60] = 1.96sqrt[0.2275 ÷ 60] = 1.96sqrt(3.792×10^-3) = 1.96×0.062 = 0.122
Lower limit = p - 0.122 = 0.65 - 0.122 = 0.528
Upper limit = p + 0.122 = 0.65 + 0.122 = 0.772
95% confidence interval is between 0.528 and 0.772
Answer: (c) 31 (d) 30 (e) 41 (f) 10
<u>Step-by-step explanation:</u>
NOTES about angles of a rhombus:
- diagonals are angle bisectors (cut the angle into 2 equal parts)
- diagonals are perpendicular to each other (90°)
- two adjacent triangles of a rhombus form an isosceles triangle
(c) Given: ∠CBD = 59°
Per rule 2 → ∠BEC = 90°
Triangle Sum Theorem: sum of the angles of a triangle = 180°
∠CBD + ∠BEC + ∠BCE = 180°
59° + 90° + ∠BCE = 180°
149° + ∠BCE = 180°
∠BCE = 31°
(d) Given: ∠BCD = 120°
Per rule 3 → ∠CBD = ∠CDB
Triangle Sum Theorem: sum of the angles of a triangle = 180°
∠CBD + ∠CDB + ∠BCD = 180°
2∠CBD + 120° = 180°
2∠CBD = 60°
∠CBD = 30°
(e) Given: ∠AED = 2x+8
Per rule 2 → ∠AED = 90°
2x+8 = 90
2x = 82
x = 41
(f) Given: ∠BCE = 3x + 3 and ∠ECD = 5x - 17
Per rule 1 → ∠BCE = ∠ECD
3x + 3 = 5x- 17
3 = 2x - 17
20 = 2x
10 = x
