Ch. 6 Quiz 6 (PSYC 2013, NWACC) – Flashcards

Q: What z-score value separates the highest 70% of the scores in a normal distribution from the lowest 30%?

Q: A normal distribution has a mean of m = 70 with s = 12. If one score is randomly selected from this distribution, what is the probability that the score will be greater than X = 55?

Q: What proportion of a normal distribution is located in the tail beyond z = 1.50?

Q: A normal distribution has a mean of m = 24 with s = 3. What is the minimum score needed to be in the top 14% of the distribution?

Q: IQ scores form a normal distribution with m = 100 and s = 15. Individuals with IQs above 140 are classified in the genius category. What proportion of the population consists of geniuses?

T/F: If one score is randomly selected from a normal distribution with m = 100 and s = 20, the probability of obtaining a score between X = 80 and X = 120 is p = 0.3413.

Q: What z-score value separates the highest 10% of the scores in a normal distribution from the lowest 90%?

Q: A vertical line drawn through a normal distribution at z = -1.00 separates the distribution into two sections, the body and the tail. What proportion of the distribution is in the body?

T/F: For a normal distribution, the proportion located between z = -1.00 and z = +1.00 is p = 34.13%

T/F: The tail is on the right side of a normal distribution for any z-score value greater than zero.

Q: A normal distribution has a mean of m = 40 with s = 10. If a vertical line is drawn through the distribution at X = 35, what proportion of the scores are on the left side of the line?

T/F: For any normal distribution, the probability of randomly selecting a z-score less than z = 1.40 is p = 0.9192.

Q: A normal distribution has a mean of m = 80 with s = 20. What score separates the highest 15% of the distribution from the rest of the scores?

Q: Which of the following accurately describes the proportions in the tails of a normal distribution?

T/F: A vertical line drawn through a normal distribution at z = -0.75 separates the distribution into two sections. The proportion in the smaller section is 0.2734.

Q: What proportion of a normal distribution is located between the mean and z = -1.40?

T/F: For a normal distribution with m = 100 and s = 20, the score that separates the top 60% of the distribution from the bottom 40% is X = 105.

T/F: For a normal distribution, the proportion located between z = -1.00 and z = +1.00 is p = 34.13%

Q: What z-score values form the boundaries for the middle 60% of a normal distribution?

Q: A vertical line is drawn through a normal distribution at z = 1.20. What proportion of the distribution is on the left-hand side of the line?

T/F: For any normal distribution, the proportion in the tail beyond z = 2.00 is p = 0.0228.

Q: A normal distribution has a mean of m = 80 with s = 20. What score separates the highest 40% of the distribution from the rest of the scores?

Q: A normal distribution has a mean of m = 100 with s = 20. If one score is randomly selected from this distribution, what is the probability that the score will have a value between X = 90 and X = 110?

T/F: For a normal distribution with m = 50 and s = 10, the line separating the highest 10% of the scores from the rest is located at X = 51.28.

T/F: A vertical line drawn through a normal distribution at z = 1.40 divides the distribution into two sections. The proportion in the smaller section is 0.0808.

Q: What proportion of a normal distribution is located between z = -1.50 and z = +1.50?

T/F: For a normal distribution, the proportion in the tail beyond z = -2.00 is equal to -0.0228.

T/F: For a normal distribution, proportions in the right-hand tail are positive, and proportions in the left-hand tail are negative.

Q: Which of the following is a requirement for a random sample?

T/F: The probability of randomly selecting a red marble from a jar that contains 10 red marbles and 20 blue marbles is 1/30.

Q: A normal distribution has a mean of m = 70 with s = 12. If one score is randomly selected from this distribution, what is the probability that the score will be greater than X = 58?

T/F: If one score is randomly selected from a normal distribution with m = 100 and s = 20, the probability of obtaining a score between X = 90 and X = 100 is p = 0.3085.

Q: A vertical line is drawn through a normal distribution at z = 0.80. What proportion of the distribution is on the right-hand side of the line?

Q: Scores on the SAT form a normal distribution with a mean of m = 500 with s = 100. If the state college only accepts students who score in the top 60% on the SAT, what is the minimum score needed to be accepted?

Q: A class consists of 10 males and 30 females. If one student is randomly selected from the class, what is the probability of selecting a male?

Q: A normal distribution has a mean of m = 100 with s = 20. If one score is randomly selected from this distribution, what is the probability that the score will have a value between X = 80 and X = 100?

Q: A normal distribution has a mean of m = 40 with s = 10. If a vertical line is drawn through the distribution at X = 55, what proportion of the scores are on the right side of the line?

Q: A vertical line drawn through a normal distribution at z = -1.00 separates the distribution into two sections, the body and the tail. What proportion of the distribution is in the body?

Q: John drives to work each morning, and the trip takes an average of m = 38 minutes. The distribution of driving times is approximately normal with a standard deviation of s = 5 minutes. For a randomly selected morning, what is the probability that John's drive to work will take less than 35 minutes?