Children who have lost some baby teeth have better arithmetic skills than children who have not lost any baby teeth. In fact, the more baby teeth a child has lost, the better his/her arithmetic skills tend to be. Which of the following statements is most likely true?a. There is a correlation here, and improving arithmetic skills causes the loss of baby teeth.
b. There is a correlation here, but there is not a direct causal relationship between losing baby teeth and arithmetic skills.
c. There is no correlation between arithmetic skills and losing baby teeth.
d. There is a correlation here, and losing baby teeth causes arithmetic skills to improve.

B. There is correlation but no direct casual relation, but losing teeth and arithmetic skills.

Step-by-step explanation:

Given:

Correlation between lost of baby teeth and arithmetic skills.

Solution:

Correlation and causality concepts are so used here.

Correlation is the relationship between two variables to get or to predict information.

Correlation is not always causation.

So here the correlation is used to predict the arithmetic skills based on lost teeth.

i.e. More teeth lost more arithmetic skills.

Causality means change in one variable changes value of other variable.

So it gives direct causal relation between the variables.

Here they given relationship between the children lost teeth and arithmetic skills  to predict information.

But ,there no actual imply on correlation.

Arithmetic skills can also depends upon third variable.

Hence there is no direct causal relationship between them.

answer: 60

step-by-step explanation:

1/2a + (2/3×30)   = 50

1/2a + 20 = 50

1/2a = 30

a = 60