FiltersDone

Question type

Essay

Multiple Choice

Short Answer

True False

Matching

Exam 6: The Normal Probability Distribution

Show Answer

Share

---

All types

Filters

Study FlashcardsPractice ExamLearn

Question 51

True/False

Review LaterAdd Note

Review Later

The mean and standard deviation of a normally distributed random variable, which has been "standardized," are 1 and 0, respectively.

A) True
B) False

Correct Answer

verified

Show Answer

Question 52

Short Answer

Review LaterAdd Note

Review Later

Pacific Salmon Narrative The owner of a fish market determined that the average weight for a Pacific salmon is 3.6 kg, with a standard deviation of 0.8 kg. Assume the weights of the salmon are normally distributed. -Refer to Pacific Salmon Narrative. What is the probability that a randomly selected salmon will weigh less than 3.2 kg?

Correct Answer

verified

Show Answer

Question 53

Essay

Review LaterAdd Note

Let x denote a normal random variable with mean 30 and standard deviation 5. What x-value is the 67th percentile of this distribution?

Which of the following distributions is considered to be the cornerstone distribution of statistical inference?

Let be a z-score that is unknown but identifiable by position and area. If the area to the right of is 0.8849, the value of is 1.2.

A car dealership has found that the length of time before a major repair is required on the new cars it sells is normally distributed, with a mean of 36 months and a standard deviation of 9 months. If the dealer wants only 5% of the cars to fail before the end of the warranty period, for how many months should the cars be guaranteed?

Many different types of continuous random variables give rise to a large variety of probability density functions. Which of those listed below are generated by such variables?

Given a normal random variable x with mean and standard deviation , the mean of the standard normal random variable z associated with x is 1.

Which of the following is a valid statement about the mean, median, and mode?

x is a normally distributed random variable with a mean of 8.20 and variance of 4.41, and P(x > b) = 0.08. What is the value of b?

If the random variable X is normally distributed, with a mean of 75 and a standard deviation of 8, which of the following values is the probability that X is greater than or equal to 75?

Water Usage Narrative The mayor of the city of Windsor was informed that household water usage is a normally distributed random variable with a mean of 95 litres and a standard deviation of 16 litres per day. -Refer to Water Usage Narrative. The mayor advertised on a local TV channel for about 3 weeks his intention to give a tax rebate to the 20% lowest water users. If the advertisement lowered the mean usage of 95 litres to 87 litres, what should the adjusted litres-per-day cut-off be?

Continuous random variables can assume infinitely many values corresponding to points on a line interval.

If Z is a standard normal random variable, then which of these values is P(-1.75 Z -1.25) ?

Canada Revenue Agency Audits Narrative How does Canada Revenue Agency decide on the percentage of income tax returns to audit for each province? Suppose the Agency does it by randomly selecting 50 values from a normal distribution with a mean equal to 1.25% and a standard deviation equal to 0.4%. -Refer to Canada Revenue Agency Audits Narrative. What is the probability that a particular province will have more than 2% of its income tax returns audited?

The normal probability distribution is right-skewed for large values of the standard deviation , and left-skewed for small values of .

The left half of the normal curve is slightly smaller than the right half.

If Z is a standard normal random variable, then the area between z = 0.0 and z =1.30 is 0.4032, while the area between z = 0.0 and z = 1.50 is 0.4332. What is the area between z = -1.30 and z = 1.50?

Given that Z is a standard normal random variable, which of the following is the value of P(-1.0 Z 1.5) ?

Given a normal random variable x with mean of 82 and standard deviation of 12, the value of the standard normal random variable z associated with x = 70 is smaller than 0.