Intro to Stats - Midterm review

A z-score tells you...

• the standard deviation of a sampling distribution.
• the original raw score on which it is based.
• if the distribution it comes from is normal.
• how many standard deviations away from the mean a score lies.

A test is given that has a mean of 70 and a standard deviation of 13. If a student's Z-score is +1, the student's score before conversion was:

• 70
• 83
• 57
• Cannot be determined from the information given.

What proportion of the standard normal curve falls above a z score of 1.33? (Rounded to the nearest two decimal places)

• 0.9082

• 0.0918

• 0.1514

• 0.0214

Based on the normal distribution, use a z-table to find P( |z| < 1.2).

• 0.1151

• 0.8849

• 0.7698

• none of these

A national achievement test is administered annually to 3rd graders. The test has a mean score of 100 and a standard deviation of 15. If Jane's z-score is 1.20, what was her score on the test?

• 82
• 88
• 100
• 118

In a factory, the weight of the concrete poured into a mold by a machine follows a normal distribution with a mean of 1150 pounds and a standard deviation of 22 pounds. Approximately 95% of molds filled by this machine will hold weights in what interval? 

• 1084 to 1216 pounds 
• 1106 to 1150 pounds 
• 1106 to 1194 pounds 
• 1128 to 1172 pounds

Pat and Chris both took a spatial abilities test (mean = 80, std. dev. = 8).  Pat scores a 76 and Chris scored a 94.  What percent of individuals would score between Pat and Chris? 

• 26.8%
• 96%
• 65.1%
• 4%

At a local high school, GPA's are normally distributed with a mean of 2.9 and standard deviation of 0.6. What is the GPA of the highest 2.5% of the students?

• 4.1 
• 4.1 or higher
• 4.7
• 4.5 or higher

The histogram shows the birth weights of 100 new born babies.  How many babies weighed 8 pounds or more?

• 22
• 23
• 30
• 45

Tags

CCSS.2.MD.D.9

What can be said about the histogram?

• normal
• skewed right
• skewed left
• none of these