Which of the following can be reasonably modeled by a normal distribution?

The favorite colors of students in a kindergarten class
A

The heights of tomato plants that were all planted on the same day
B

The percent of employees from a company who attended a company retreat
C

The average number of siblings of all students at a particular high school
D

The parental guidance ratings (G, PG, PG-13, R) of movies filmed in 2019
E

C?

The distribution of the number of moths captured per night by a certain moth trap is approximately normal with mean 103. If 28 percent of the captures fall below 76 per night, which of the following equations can be used to find σ, the standard deviation of the distribution?
0.28=103−76/σ
A

0.28=76−103/σ
B

−0.58=103−76/σ
C

−0.58=76−103/σ
D

0.58=76−103/σ
E

B?
Answer choices C and B

User Icon for PsyDAG PsyDAG answered
5 years ago

Disagree with both.

User Icon for Anonymous Anonymous answered
5 years ago

B ( because it is heights?)and D because -.58 would be the z-score of .281?

User Icon for Anonymous Anonymous answered
4 years ago

The answer to the first one should be narrowed down to A or D but answer choice A uses a very small sample size so you cannot expect it to look normal. D uses all students in a particular high school so you can expect this large sample to be modeled by a normal distribution.

User Icon for Anonymous Anonymous answered
4 years ago

Nevermind, the answer should be B. Upon further reading you will notice that D is only displaying a single number and that is the average amount of siblings. Displaying a single number will not give you a normal distribution.

User Icon for Anonymous Anonymous answered
4 years ago

The first question should be B because you need a continuous variable to make a Normal distribution and all of the other options are discrete variables.

User Icon for Anonymous Anonymous answered
4 years ago

B is the right answer but not because of that ^

Its just because biological populations are usually Normally distributed because of nature.
A and E are categorical so they could not be represented by a Normal curve and C seems like it could only be one value of the percent of employees. D would most likely be strongly skewed to the right because there would be a lot of people with 0, 1, 2, or 3 siblings and then only a couple would have more and none could have a negative amount.

User Icon for Anonymous Anonymous answered
4 years ago

I believe the answer is B because it can be measured quantitatively and heights are usually normal when gender is not involved.

User Icon for Kishon Tennassee 34986 Kishon Tennassee 34986 answered
4 years ago

40 employees in an office wear eyeglasses. 23 have single-vision correction, and 17 wear bifocals. If two employees are selected at random from this group, what is the probability that both of them wear bifocals? What is the probability that both have single-vision correction?

User Icon for Xavier Xavier answered
4 years ago

Show how prime numbers can be multiplied to equal 27. Help

User Icon for Adam Adam answered
4 years ago

Nevermind, the answer should be B. Upon further reading you will notice that D is only displaying a single number and that is the average amount of siblings. Displaying a single number will not give you a normal distribution.