OSTP Grades 6-8 Statistics and Probability Practice

Practice playeasy

A shipping clerk weighed $14$ packages. The frequency table shows each weight and how many packages had that weight.
$\begin{array}{c|c} \text{Weight (lb)} & \text{Number of packages} \\ \hline 2 & 3 \\ 7 & 2 \\ 12 & 5 \\ 17 & 2 \\ 22 & 2 \end{array}$

What is the median package weight?

There are $14$ weights. Listing every weight from least to greatest, the $7$ th and $8$ th values are both $12$ , so the median is $12$ pounds.

Practice playeasy

Two fair coins are flipped. How many outcomes are in the sample space?

Each coin has $2$ outcomes, so the sample space has $2 \times 2 = 4$ outcomes: HH, HT, TH, TT.

Practice playeasy

A class answered the statistical question "How many pages did you read this week?" The answers were $12, 15, 15, 18, 20, 15$ . How many students were interviewed?

Each answer in the list is one student. Count every value, including repeats: there are $6$ answers, so $6$ students were interviewed.

Practice playeasy

Which of these is NOT a statistical question?

A statistical question anticipates variability: many people or things can give different answers. "How many pets does my family own?" asks about one family, so it has one answer. It is not a statistical question.

Practice playmedium

Five test scores are $70$ , $78$ , $84$ , $90$ , and $96$ . One score is removed from the data set, but which score was removed is not stated. How does this affect the mean?

The mean of the five given scores can be found, but removing a different score changes the mean in different ways. Without knowing which score was removed, the effect cannot be determined.

Practice playeasy

Seven test scores are $70\textsf{,}$ $75\textsf{,}$ $88\textsf{,}$ $85\textsf{,}$ $90\textsf{,}$ $65\textsf{,}$ and $87\textsf{.}$ What is the mean score?

Mean $= \dfrac{70 + 75 + 88 + 85 + 90 + 65 + 87}{7} = \dfrac{560}{7} = 80$ .

Practice playeasy

Find the range of 10, 3, 15, 6.

Range $= \max - \min = 15 - 3 = 12$ .

Practice playeasy

The distances, in miles, run on seven days are $14\textsf{,}$ $6\textsf{,}$ $20\textsf{,}$ $9\textsf{,}$ $11\textsf{,}$ $18\textsf{,}$ and $6\textsf{.}$ What is the median distance?

In order, the values are $6\textsf{,}$ $6\textsf{,}$ $9\textsf{,}$ $11\textsf{,}$ $14\textsf{,}$ $18\textsf{,}$ $20\textsf{.}$ The median is the middle value, $11\textsf{.}$

OSTP Grades 6-8 Statistics and Probability. Practice it free.

Statistics and Probability skills

statistical measures

distributions

bivariate data

dot plots and box plots

probability

Topics mapped to this domain

Central Measures from Tally Charts (ACT)

Compound probability

Describing a Data Distribution

Identifying Statistical Questions

Mean change from data set edits

Mean from a data list

Measures of center and variability

Median from a data list

One-event probability word problems

Probability basics

Probability from number sets

Probability of simple events

8 free questions · 0/0 correct

Turn statistics and probability into game time.

More Grades 6-8 domains