Typical machined parts require very tight tolerance in variance in order to work properly in their application. We took a sample of the length (in mm.) of 100 units from a large production run and got the following statistics: sample mean = 499.97, sample variance = 6.52 What is the 99% confidence interval estimate for the true population VARIANCE in unit length?
a. (499.30, 500.64)
b. (4.97, 8.93)
c. (4.64, 9.71)
d. (4.79, 9.32)
e. none of the above

Use the following statements to write a compound statement for the conjunction or disjunction. then find its truth value. p: an isosceles triangle has two congruent sides. q: a right angle measures 90° r: four points are always coplanar. s: a decagon has 12 sides. a) a right angle measures 90° or an isosceles triangle has two congruent sides; true. b) a right angle measures 90° and an isosceles triangle has two congruent sides; true. c) a right angle measures 90° and an isosceles triangle does not have two congruent sides; false. d) a right angle measures 90° or an isosceles triangle does not have two congruent sides; true.

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The trapezoid is composed of a rectangle and two triangles. what is the area of the rectangle? what is the total area of the triangles? what is the area of the trapezoid? a) 48 cm2; 32 cm2; 80 cm 2 b) 48 cm2; 16 cm2; 64 cm 2 c) 128 cm2; 32 cm2; 160 cm 2 d) 128 cm2; 16 cm2; 144 cm 2