Unit 8 Practice/Homework

Find the value of q.

Find $E(x)$.

Find k.

Find the probability that exactly k students have cellphones.

Find the probability that fewer than k students have cellphones.

Find the probability that at least k students have cellphones.

On the following diagram, shade in the region representing $P(X≥45)$.

Find $P(X≥45)$.

Given that $P(X≤k)=0.8$, find the value of k.

Draw a diagram that shows this information.

Find the probability that a shoebox, chosen at random, is sold.

Calculate the manufacturer’s expected daily income from these sales.

Find the expected number of defective toys.

Find the probability that there is at least one defective toy in the sample.

Given that there is at least one defective toy in the sample, find the probability that there are at most three defective toys.

Given that 5.3% of newborn puppies have a low birth weight, find w.

A newborn puppy has a low birth weight. Find the probability that the puppy weighs at least 2.15 kg.

Find the probability that a student, chosen at random arrives at least 60 minutes after the school opens.

Find the probability that a student, chosen at random arrives between 45 minutes and 55 minutes after the school opens.

A second school, Poe MS, also opens at 08:00 every morning. The arrival times of the students at this school follows exactly the same distribution as Key MS. Given that, on one morning, 15 students arrive at least 60 minutes after the school opens, estimate the number of students at Poe MS.

Find the expected number of questions Jack answers correctly.

Jack answers exactly four questions correctly;

Jack answers more than four questions correctly.

A student is selected at random. Find the probability that the student completes the task in less than 48 minutes.

The probability a student takes between k and 48 minutes is 0.4. Find the value of k.

Find the probability that a car selected at random receives a speeding ticket.

Estimate the whole number of cars that will receive a speeding ticket from a random sample of 150 cars.

Given that a car receives a speeding ticket, find the probability that it was traveling more than 50 km per hour.

Exactly one defective motor

At least two defective motors

Given that there are at least two defective motors in the box, find the probability that there are at most four defective motors.

Find the probability that James will receive at least one but no more than fifteen defective motors in his order.