**Making inferences from a random sample worksheet :**

Worksheet on making inferences from a random sample is much useful to the students who would like to study the stuff sampling and inferences.

1. A manager samples the receipts of every fifth person who goes through the line. Out of 50 people, 4 had a mispriced item. If 600 people go to this store each day, how many people can we expect to have a mispriced item ?

2. The number of pets owned by a random sample of students at Park Middle school is shown below.

9, 2, 0, 4, 6, 3, 3, 2, 5

3. A shipment to a warehouse consists of 3,500 MP3 players. The manager chooses a random sample of 50 MP3 players and finds that 3 are defective. How many MP3 players in the shipment are likely to be defective ?

4. A manager samples the receipts of every fifth person who goes through the line. Out of 50 people, 4 had a mispriced item. If 600 people go to this store each day, how many people can we expect to have a mispriced item ?

**Problem 1 : **

Rosee asked students on the lunch line how many books they had in their backpacks. She recorded the data as a list: 2, 6, 1, 0, 4, 1, 4, 2, 2.

(i) Make a dot plot for the books carried by this sample of students.

**Step 1 : **

Make a real number line.

In the given data, we have values range from from 0 to 6.

So we have to use a scale from 0 to 6.

**Step 2 : **

Place a dot above each number on the number line for each time it appears in the data set.

(ii) How are the number of dots you plotted related to the number of data values ?

They are the same. Each dot represents one data value.

(iii) What could Rosee do to improve the quality of her data ?

Rosee could increase the size of her sample.

**Problem 2 : **

The number of pets owned by a random sample of students at Park Middle school is shown below.

9, 2, 0, 4, 6, 3, 3, 2, 5

(i) Use the data to make a box plot.

**Step 1 :**

Order the data from least to greatest. Then find the least and greatest values, the median, and the lower and upper quartiles.

**Step 2 : **

The lower and upper quartiles can be calculated by finding the medians of each “half” of the number line that includes all the data.

**Step 3 : **

Draw a number line that includes all the data values.

Plot a point for each of the values found in Step 1.

Draw a box from the lower to upper quartile. Inside the box, draw a vertical line through the median. Finally, draw the whiskers by connecting the least and greatest values to the box.

(ii) What is a good measure for the most likely number of pets ?

A good measure for the most likely number of pets is 3.

(iii) How many pets does every student have ?

Almost every student in Parkview has at least 1 pet

**Problem 3 : **

A shipment to a warehouse consists of 3,500 MP3 players. The manager chooses a random sample of 50 MP3 players and finds that 3 are defective. How many MP3 players in the shipment are likely to be defective ?

**Solution :**

It is reasonable to make a prediction about the population, because this sample is random.

**Step 1 : **

Set up a proportion.

**Step 2 : **

Substitute values into the proportion.

Substitute known values. Let x be the number of defective MP3 players in the population.

3 / 50 = x / 3500

50 x 70 = 3500, so multiply the numerator and denominator of the fraction 3/50 by 70.

(3x70) / (50x70) = x / 3500

210 / 3500 = x / 3500

210 = x

Based on the sample, you can predict that 210 MP3 players in the shipment would be defective.

**Problem 4 : **

A manager samples the receipts of every fifth person who goes through the line. Out of 50 people, 4 had a mispriced item. If 600 people go to this store each day, how many people can we expect to have a mispriced item ?

**Solution :**

**Step 1 : **

Set up a proportion.

**Step 2 :**

Substitute values into the proportion.

Substitute known values. Let x be the number of mispriced items in the population.

4 / 50 = x / 600

50 x 12 = 600, so multiply the numerator and denominator of the fraction 4/50 by 12.

(4x12) / (50x12) = x / 600

48 / 600 = x / 600

48 = x

Based on the sample, we can expect 48 mispriced items in the population of 600 people.

After having gone through the stuff given above, we hope that the students would have understood "Making inferences from a random sample worksheet".

Apart from the stuff given above, if you want to know more about "Making inferences from a random sample", please click here

Apart from the stuff "Making inferences from a random sample worksheet", if you need any other stuff in math, please use our google custom search here.

HTML Comment Box is loading comments...

**WORD PROBLEMS**

**HCF and LCM word problems**

**Word problems on simple equations **

**Word problems on linear equations **

**Word problems on quadratic equations**

**Area and perimeter word problems**

**Word problems on direct variation and inverse variation **

**Word problems on comparing rates**

**Converting customary units word problems **

**Converting metric units word problems**

**Word problems on simple interest**

**Word problems on compound interest**

**Word problems on types of angles **

**Complementary and supplementary angles word problems**

**Markup and markdown word problems **

**Word problems on mixed fractrions**

**One step equation word problems**

**Linear inequalities word problems**

**Ratio and proportion word problems**

**Word problems on sets and venn diagrams**

**Pythagorean theorem word problems**

**Percent of a number word problems**

**Word problems on constant speed**

**Word problems on average speed **

**Word problems on sum of the angles of a triangle is 180 degree**

**OTHER TOPICS **

**Time, speed and distance shortcuts**

**Ratio and proportion shortcuts**

**Domain and range of rational functions**

**Domain and range of rational functions with holes**

**Graphing rational functions with holes**

**Converting repeating decimals in to fractions**

**Decimal representation of rational numbers**

**Finding square root using long division**

**L.C.M method to solve time and work problems**

**Translating the word problems in to algebraic expressions**

**Remainder when 2 power 256 is divided by 17**

**Remainder when 17 power 23 is divided by 16**

**Sum of all three digit numbers divisible by 6**

**Sum of all three digit numbers divisible by 7**

**Sum of all three digit numbers divisible by 8**

**Sum of all three digit numbers formed using 1, 3, 4**

**Sum of all three four digit numbers formed with non zero digits**