Select all statements that are true for density curves.
the curve is on or above the horizontal axis.
the total area under the curve is 1
the curve is symmetric and single peaked
the proportion of data values between two numbers and is the area under the curve between a and b.
the curve satisfies the 68.95.99.7% rule.

The curve is on or above the horizontal axis ⇒ 1st

The total area under the curve is 1 ⇒ 2nd

The proportion of data values between two numbers and is the area

under the curve between a and b ⇒ 4th

Step-by-step explanation:

* Lets explain the meaning of density curve

- Density curve  is a mathematical model for a distribution of a variable

- It is another type of graph that represents a quantitative variables

- It describes the overall pattern of a distribution

- Its area is always on or above the horizontal axis

- Its area under the curve is exactly 1

- It can come in many shapes - symmetric, right-skewed, left-skewed

- The area under the curve and above any range of values on the

  horizontal axis is the proportion of all observations that fall in

  that range

- Ex: density curve describes the probability distribution of a

 continuous random variable

 The probability of any event is the area under the curve and above

 the values that make up the event.

* Now lets chose the true statements

# The curve is on or above the horizontal axis

# The total area under the curve is 1

# The proportion of data values between two numbers and is the area

  under the curve between a and b

answer: there are x+184 pages in olivia's book.

step-by-step explanation:

let the total number of pages in the book which olive has already read be x.

then if olive has 184 pages left to read, then the total number of pages are in olive's book= pages she has read+pages she has left to read

therefore, the total number of pages in olivia's book=

hence, there are x+184 pages in olivia's book.