# Statistics and Probability Answers

Probability

Probability

### Three students are arguing, Chad says, "I think the probability is 1 out of 2." Tien says, "No, it is 40 over 80." Falicia says, "It is 50%." What do you say to the students?

Normal distributions

### Consider two independent populations that are normally distributions. A simple random sample of $$\displaystyle{n}_{{1}}={41}$$ from the first population showed $$\displaystyle\overline{{x}}_{{11}}={33}$$, and a simple random of size $$\displaystyle{n}_{{2}}={48}$$ from the second population showed $$\displaystyle\overline{{x}}_{{2}}={32}$$ Suppose $$\displaystyle{s}_{{1}}={9}{s}_{{1}}={9}{\quad\text{and}\quad}{s}_{{2}}={10}{s}_{{2}}={10}$$, find a 98% confidence interval for $$\displaystyle\mu_{{1}}−\mu_{{2}}\mu_{{1}}-\mu_{{2}}$$. (Round answers to two decimal places.) margin of error-? lower limit-? upper limit-?

Data distributions

Study design

Study design

Two-way tables

Scatterplots

### A nutritionist collects the weight of college students in the first semester, then again in the second semester. What is the best way to visually present this data? a) Line Graphs b) Scatterplots c) Bar Graphs d) Pie Charts

Normal distributions

### Explain some of the important characteristics of a normal distribution.

Data distributions

Probability

### A hip joint replacement part is being stress-tested in a laboratory. The probability of successfully completing the test is 0.883. 11 randomly and independently chosen parts are tested. What is the probability that exactly two of the 11 parts successfully complete the test?

Binomial probability

Scatterplots

### Make a scatterplot for the data. Height and Weight of Females Height (in.): 58, 60, 62, 64, 65, 66, 68, 70, 72 Weight (lb): 115, 120, 125, 133, 136, 115, 146, 153, 159

Normal distributions

Probability

Probability

Scatterplots

Two-way tables

Scatterplots