Filters
Question type

Study Flashcards

Using the standard Normal distribution tables, the area under the standard Normal curve corresponding to Z > -1.62 is:


A) 0.0044.
B) 0.0526.
C) 0.9474.
D) 0.9956.

Correct Answer

verifed

verified

The scores on the Wechsler Adult Intelligence Scale are approximately Normal, with = 100 and =15. If you scored 130, your score would be higher than approximately what percent of adults?


A) 92%
B) 95%
C) 97.5%
D) 99.7%

Correct Answer

verifed

verified

Scores on a university exam are Normally distributed, with a mean of 78 and a standard deviation of 8. The professor teaching the class declares that a score of 70 or higher is required for a grade of at least C. Using the 68-95-99.7 rule, what percent of students score below 62?


A) 2.5%
B) 5%
C) 16%
D) 32%

Correct Answer

verifed

verified

A high-profile consulting company chooses its new entry-level employees from a pool of recent college graduates using a five-step interview process. Unfortunately, there are usually more candidates who complete the interview process than the number of new positions that are available. As a result, cumulative GPA is used as a tie-breaker. GPAs for the successful interviewees are Normally distributed, with a mean of 3.3 and a standard deviation of 0.4. What proportion of candidates have a GPA under 3.0?


A) 0.023
B) 0.227
C) 0.551
D) 0.773

Correct Answer

verifed

verified

A Normal distribution:


A) is symmetric.
B) can be completely specified by a mean, , and a standard deviation, .
C) has an area of exactly 1 underneath the density curve.
D) All of the answer options are correct.

Correct Answer

verifed

verified

The duration (in days) of human pregnancies follows approximately the N(266,16) distribution. What proportion of pregnancy durations is more than 270 days?


A) 0.334
B) 0.401
C) 0.599
D) 0.621

Correct Answer

verifed

verified

The scores on the Wechsler Adult Intelligence Scale are approximately Normal, with = 100 and = 15. The proportion of adults with scores above 110 is closest to:


A) 0.08.
B) 0.10.
C) 0.25.
D) 0.35.

Correct Answer

verifed

verified

Scores on a university exam are Normally distributed, with a mean of 78 and a standard deviation of 8. The professor teaching the class declares that a score of 70 or higher is required for a grade of at least C. Using the 68-95-99.7 rule, what percent of students failed to earn a grade of at least C?


A) 32%
B) 16%
C) 5%
D) 2.5%

Correct Answer

verifed

verified

Birth weights at a local hospital have a Normal distribution, with a mean of 110 oz and a standard deviation of 15 oz. The proportion of infants with birth weights above 125 oz is:


A) 0.500.
B) 0.159.
C) 0.341.
D) 0.841.

Correct Answer

verifed

verified

Using the standard Normal distribution tables, the area under the standard Normal curve corresponding to -0.5 < Z < 1.2 is:


A) 0.3085.
B) 0.8849.
C) 0.5764.
D) 0.2815.

Correct Answer

verifed

verified

You recently took a statistics exam in a large class. The instructor tells the class that the scores were Normally distributed, with a mean of 72 (out of 100) and a standard deviation of 12. Your score was 90. Your friend had a time conflict and took a course with another instructor. Your friend had a score of 75 on a test, with a mean of 60 and a standard deviation of 10. What can you conclude?


A) You clearly ranked better.
B) You and your friend ranked equally well.
C) Your friend actually ranked better.
D) The tests cannot be compared.

Correct Answer

verifed

verified

The duration (in days) of human pregnancies follows approximately the N(266, 16) distribution. How many days would a human pregnancy need to last to be among the top 10% of all pregnancy durations?


A) 239.7 days
B) 245.5 days
C) 286.5 days
D) 292.3 days

Correct Answer

verifed

verified

Scores on the SAT verbal test in recent years follow approximately the N(515, 109) distribution. How high must a student score in order to place in the top 5% of all students taking the SAT?


A) 301
B) 336
C) 694
D) 729

Correct Answer

verifed

verified

The scores on the Wechsler Adult Intelligence Scale are approximately Normal, with = 100 and = 15. The proportion of adults with scores between 80 and 120 is closest to:


A) 0.50.
B) 0.66.
C) 0.82.
D) 0.99.

Correct Answer

verifed

verified

You recently took a statistics exam in a large class with n = 500 students. The instructor tells the class that the scores were Normally distributed, with a mean of 72 (out of 100) and a standard deviation of 8, but when you talk to other students in the class, you find out that more than 30 students have scores below 45. That violates which rule for the Normal distribution?


A) the 1-2-3 rule
B) the 30-60-90 rule
C) the 68-95-99.7 rule
D) It does not violate any rule; anything can happen.

Correct Answer

verifed

verified

Birth weights at a local hospital have a Normal distribution, with a mean of 110 oz and a standard deviation of 15 oz. The proportion of infants with birth weights between 125 oz and 140 oz is:


A) 0.819.
B) 0.636.
C) 0.477.
D) 0.136.

Correct Answer

verifed

verified

A high-profile consulting company chooses its new entry-level employees from a pool of recent college graduates using a five-step interview process. Unfortunately, there are usually more candidates who complete the interview process than the number of new positions that are available. As a result, cumulative GPA is used as a tie-breaker. GPAs for the successful interviewees are Normally distributed, with a mean of 3.3 and a standard deviation of 0.4. What percent of candidates have a GPA above 3.9?


A) 2.3%
B) 6.7%
C) 93.3%
D) 97.7%

Correct Answer

verifed

verified

Showing 21 - 37 of 37

Related Exams

Show Answer