Grade 7 Unit 4 District Assessment 2020-21 Question: 1 Jacob saw a model of a building that will be built in his city. The model has a height of 40 centimeters and will be built to a scale of 1:50. What is the actual height of the building? (1 m = 100 cm)

Find the center and the radius of the circle with the equation: x^2-2x+y^2+4y+1=0?

What is the ratio of the length of an object in yards to the length of the same object in miles?

Amachine that produces a special type of transistor (a component of computers) has a 2% defective rate. the production is considered a random process where each transistor is independent of the others. (a) what is the probability that the 10th transistor produced is the first with a defect? (b) what is the probability that the machine produces no defective transistors in a batch of 100? (c) on average, how many transistors would you expect to be produced before the first with a defect? what is the standard deviation? (d) another machine that also produces transistors has a 5% defective rate where each transistor is produced independent of the others. on average how many transistors would you expect to be produced with this machine before the first with a defect? what is the standard deviation? (e) based on your answers to parts (c) and (d), how does increasing the probability of an event a↵ect the mean and standard deviation of the wait time until success?