Data and Stats Revisions - Exam 1 Quiz 2

The table shows average body weight (in kg) and average brain weight (in g) of nine animal species.

A least squares regression line is fitted to the data using body weight as the independent variable. The equation of the least squares regression line is
brain weight = 49.4 +2.68 x body weight

This equation is then used to predict the brain weight (in g) of the baboon. The residual value (in g) for this prediction will be closest to

• -102

• -78

• 78

• 102

The mathematics achievement level(TIMSS score) for grade 8 students and the general rate of Internet use (%) for 10 countries are displayed in the scatter plot below.

To linearise the data, it would be best to plot

• mathematics achievement against Internet use.

• log(mathematics achievement) against Internet use.

• mathematics achievement against log(Internet use).

• mathematics achievement against (Internet use)².

The time series plot below shows the growth in Internet use (%) in a country from 1989 to 1997 inclusive.

If a three-median line is fitted to the data it would show that, on average, the increase in Internet use per year was closest to

• 0.36%

• 0.41%

• 0.45%

• 0.49%

The annual profit increases for ten companies are given below. The increases are expressed as percentages:
5 8 8 7 9

3 5 4 6 4

The interquartile range (IQR) of these annual profit increases is

• 3

• 4

• 6

• 9

The annual profit increases for ten companies are given below. The increases are expressed as percentages:
5 8 8 7 9

3 5 4 6 4

This data can best be displayed using a

• histogram

• box plot

• scatterplot

• parallel stem plot

Samples of a freshwater fish were taken upstream and downstream in a river. The weight (in g) of each fish was recorded and is displayed in the boxplots shown.
From the boxplots, it can be concluded that the weights of the fish taken downstream are generally

• less than the weights of those taken upstream and less variable.

• less than the weights of those taken upstream and more variable.

• more than the weights of those taken upstream and less variable.

• more than the weights of those taken upstream and more variable.

Samples of a freshwater fish were taken upstream and downstream in a river. The weight (in g) of each fish was recorded and is displayed in the boxplots shown.
Using the 68-95-99.7% rule, for the sample of fish taken downstream, the standard deviation is closest to

• 35g

• 40g

• 45g

• 65g

The heights of a very large sample of women aged 80 years or more were recorded and were found to follow a normal distribution. The mean of the distribution was 164cm and the standard deviation was 4.5cm.

The percentage of these women with a height between 159.5cm and 173cm is closest to

• 47.5%

• 68%

• 81.5%

• 95%

A survey of 760 tertiary students was undertaken. The attendance category of each student together with their gender was recorded. The data is shown in the table below.
The percentage of full time students who are female is closest to

• 42%

• 47%

• 53%

• 72%

The weight (in kg) and age (in years) of ten residents at a nursing home were recorded. The data is displayed on the scatterplot below. A regression line has been fitted by eye to the data.
The regression line predicts that the weight of an 84 year old resident would be closest to

• 60kg

• 61kg

• 63kg

• 65kg