1. An online bookstore is having a one-day sale. Softcover books are $4, hardcover books are $7, magazines are $3, and all digital downloads of books are $2. Let's say 150 customers purchased books in one form or another that day. Below are the frequencies in which customers purchased books:

Books: Purchases:
Softcover 42
Hardcover 28
Magazine 23
Digital Download 57

Based on the data above, which is the correct relative frequency with discrete random variable X = "the amount of money for a book?"

A. xP(X = x)
2 0.38
3 0.15
4 0.28
7 0.19

B. xP(X = x)
2 0.15
3 0.38
4 0.19
7 0.28

C. xP(X = x)
2 0.28
3 0.19
4 0.15
7 0.38

D. xP(X = x)
1 0.38
2 0.15
3 0.28
4 0.19

Branliest to correct answer no guessing please really need help

answer: 457.14

step-by-step explanation:

205 - 45 = 160

160 / .35 = 457.142857

i would pic false cause it goes down towards negative

step-by-step explanation:

introduction, methodology, results, discussion

step-by-step explanation:

an observational study is one which consists of actual observation to record data and then analyse the data.

there are a number of factors that should be analyzed before starting an observational study.

the main four factors are:

i) introduction:   this should be analysed to check whether the purpose of the study is correctly established and the data recorded are appropriate for the study

methodology:   the method of collecting the data, such as whether randomly selected, and whether sample size matches with the population to be studied, whether questions asked are easy to answer by common men, etc.

results: then results such as summary of data with comments should be studied thoroughly

discussion:   the last is the discussion, this can be either by management people or persons who are all interested , etc.

answer: are you

step-by-step explanation: