Plug in n = 7 in the equation c(n) = 50 + 4n, to get c(7) = 50 + 4\cdot 7 = 50 + 28 = 78.

So, when the number of visits is 7, the monthly cost in dollars will be $78.

I found an answer from web.stanford.edu

COMPUTER AGE STATISTICAL INFERENCE

next to the **number**, the page **number** of the referenced location is **given** in
parenthesis. ... interest, perhaps the automobile accident **rates** in the **n** D **50**
states. The **mean** ... We might instead try a quadratic regression y D Oˇ0 **C** Oˇ1x **C**
Oˇ2x2, or a cubic ... This **brings us** to an aspect of Fisherian inference neither
Bayesian nor.

For more information, see COMPUTER AGE STATISTICAL INFERENCE

I found an answer from stackoverflow.com

PHP - Notice: Undefined index: - Stack Overflow

Before you extract **values** from $_POST , you should **check** if they exist. You
could use the isset **function** for this (http://php.net/manual/en/**function**.isset.php).

For more information, see PHP - Notice: Undefined index: - Stack Overflow

I found an answer from quizizz.com

Unit 4 Lesson 11 Practice Problems Quiz - Quizizz

**C gives** the **cost**, in **dollars**, of a **cafeteria meal plan** as a **function** of the number ...
is represented by the equation **C**(n)= 4+3n. Find **C**(n)=31. answer choices. 8. **9**.

For more information, see Unit 4 Lesson 11 Practice Problems Quiz - Quizizz