Date | May 2017 | Marks available | 2 | Reference code | 17M.1.sl.TZ1.6 |
Level | SL only | Paper | 1 | Time zone | TZ1 |
Command term | Find | Question number | 6 | Adapted from | N/A |
Question
In a school, students in grades 9 to 12 were asked to select their preferred drink. The choices were milk, juice and water. The data obtained are organized in the following table.
A \({\chi ^2}\) test is carried out at the 5% significance level with hypotheses:
\[\begin{array}{*{20}{l}} {{{\text{H}}_{\text{0}}}{\text{: the preferred drink is independent of the grade}}} \\ {{{\text{H}}_{\text{1}}}{\text{: the preferred drink is not independent of the grade}}} \end{array}\]
The \({\chi ^2}\) critical value for this test is 12.6.
Write down the value of \(x\).
Write down the number of degrees of freedom for this test.
Use your graphic display calculator to find the \({\chi ^2}\) statistic for this test.
State the conclusion for this test. Give a reason for your answer.
Markscheme
30 (A1) (C1)
[1 mark]
6 (A1) (C1)
[1 mark]
\({\text{19.0 (18.9640)}} \ldots \) (A2)(ft) (C2)
Note: Follow through from part (a).
Award (A1) for truncation to 18.9.
[2 marks]
reject (do not accept) \({{\text{H}}_0}\)\(\,\,\,\)OR\(\,\,\,\)accept \({{\text{H}}_1}\) (A1)(ft)
Note: Can be written in words.
\(19.0{\text{ }}(18.9640 \ldots ) > 12.6\) (R1) (C2)
Note: Accept “\(\chi _{calc}^2 > \chi _{crit}^2\)” for the (R1) provided their \(\chi _{calc}^2\) value is explicitly seen in their part (c).
OR
\((p = ){\text{ }}0.00422{\text{ }} < {\text{(significance level = ) }}0.05\) (R1) (C2)
Note: Do not award (R0)(A1)(ft). Follow through from part (c). Numerical comparison must be seen to award the (R1).
[2 marks]
Examiners report
Syllabus sections
- 10M.1.sl.TZ1.10c: Of the 400 people Tony interviewed, 220 were male and 180 were female. 80 of the people had...
- 10M.1.sl.TZ1.10d: Tony used a 5 % level of significance for his test and obtained a p-value of 0.0634 correct...
- 10M.1.sl.TZ2.9b: Write down the number of degrees of freedom for this test.
- 10M.1.sl.TZ2.9c: Write down the critical value for this test.
- 10N.2.sl.TZ0.1B.a: Write down the null hypothesis, H0, for this test.
- 12M.2.sl.TZ1.2f: Determine whether H0 should be accepted. Justify your answer.
- 12M.1.sl.TZ2.8b: The colours of the cars were red, green, blue, black and silver. Find the number of degrees...
- 09N.2.sl.TZ0.4B, a: Write down the total number of male students.
- 09N.2.sl.TZ0.4B, b: Show that the expected frequency for males, whose favourite car colour is blue, is 12.6.
- 09M.1.sl.TZ1.6d: The critical value for the \(\chi^2\) test at the 5% significance level is 12.59. The...
- 11M.2.sl.TZ1.2B.d: A \({\chi ^2}\) test at the \(5\% \) significance level was carried out to determine whether...
- 13M.2.sl.TZ1.1b: Write down the number of degrees of freedom.
- 13M.2.sl.TZ1.1e: Use your graphic display calculator to find for the data (i) the \(\chi^2\) calculated...
- 13M.2.sl.TZ1.1d: Show that the expected number of Medium Yield crops using Fertilizer C is 17, correct to the...
- 13M.2.sl.TZ1.1f: State the conclusion of the test. Give a reason for your decision.
- SPM.1.sl.TZ0.8b: Write down the \(p\)-value for the test.
- 07N.2.sl.TZ0.4ii.d: Using your graphic display calculator, or otherwise, find the chi-squared statistic for...
- 08M.2.sl.TZ2.2i.f: The market research organization tests the survey data to determine whether the brand of...
- 10M.1.sl.TZ2.9a.ii: Write down the alternative hypothesis.
- 14M.1.sl.TZ2.8a: Find the expected frequency for the females who use public transport to get to school.
- 13N.1.sl.TZ0.8c: Write down the value of \(\chi _{calc}^2\).
- 15M.1.sl.TZ2.7b: Write down the observed number of viewers who preferred Rumba and were older than 20 years old.
- 16N.1.sl.TZ0.6c: State, giving a reason, whether the null hypothesis should be rejected.
- 16M.1.sl.TZ2.7b: A \({\chi ^{\,2}}\) test at the \(5\,\% \) significance level is used to determine whether TV...
- 16M.1.sl.TZ1.10a: The manager of a travel agency surveyed 1200 travellers. She wanted to find out whether there...
- 17M.1.sl.TZ1.6b: Write down the number of degrees of freedom for this test.
- 17M.2.sl.TZ2.1a.i: If the teacher chooses a response at random, find the probability that it is a response to...
- 17M.2.sl.TZ2.1d: Show that the expected frequency of satisfactory Calculus responses is 12.
- 17N.2.sl.TZ0.1e.ii: Write down the number of degrees of freedom.
- 18M.2.sl.TZ2.3a.ii: In a training session there are 40 basketball players. Find the expected number of players...
- 18M.2.sl.TZ2.3d.ii: For this test find the p-value.
- 10M.1.sl.TZ1.10b: Write down the number of degrees of freedom.
- 10N.2.sl.TZ0.1B.d: Show that the expected number of females that have more than 5 meals per day is 13, correct...
- 12M.1.sl.TZ2.8a: Write down the null hypothesis.
- 07M.1.sl.TZ0.8c: The number of degrees of freedom is 4. Show how this value is calculated.
- 07N.2.sl.TZ0.4ii.b: State Manuel’s null hypothesis and alternative hypothesis.
- 13N.1.sl.TZ0.8a: Write down the null hypothesis for this test.
- 15M.2.sl.TZ1.1b: Write down the number of degrees of freedom.
- 16N.1.sl.TZ0.6a: Find the expected frequency of the patients who became infected whilst in Nightingale ward.
- 17N.2.sl.TZ0.1b.ii: Write down, for \(N\), the mid-interval value of the modal class.
- 17N.2.sl.TZ0.1c.ii: Use your graphic display calculator to estimate the standard deviation of \(N\).
- 18M.2.sl.TZ1.2f: Write down the probability that this flight arrived on time.
- 18M.2.sl.TZ2.3a.i: Find the probability that a basketball player has a weight that is less than 61 kg.
- 10M.1.sl.TZ2.9d: State whether the type of coffee drunk is independent of gender. Give a reason for your answer.
- 10N.2.sl.TZ0.1B.e: Use your graphic display calculator to find the \(\chi _{calc}^2\) for this data.
- 12N.2.sl.TZ0.4e: The manager of the store wants to determine whether the screen size is independent of gender....
- 11N.2.sl.TZ0.2e: State, giving a reason, whether there is sufficient evidence at the \(5\% \) level of...
- 13M.1.sl.TZ2.6b: Find the number of degrees of freedom for this test.
- 07M.1.sl.TZ0.8a: Write a suitable null hypothesis for a \(\chi^2\) test on this data.
- 07M.1.sl.TZ0.8b: Write down the value of \(\chi^2\) for this data.
- SPM.1.sl.TZ0.8a: Find the expected number of female volleyball players under this hypothesis.
- 15M.1.sl.TZ2.7a: Write down the null hypothesis for this test.
- 15M.1.sl.TZ2.7d: The producer claims that the type of Latin dance a viewer preferred is independent of their...
- 15M.2.sl.TZ1.1d: Find (i) the \({\chi ^2}\) statistic; (ii) the associated \(p\)-value for the test.
- 17M.2.sl.TZ2.1b: The teacher groups the responses by topic, and chooses two responses to the Logic question....
- 17M.2.sl.TZ2.1c: State the null hypothesis for this test.
- 17N.2.sl.TZ0.1d: Find the expected frequency of students choosing the Science category and obtaining 31 to 40...
- 17N.2.sl.TZ0.1e.i: Write down the null hypothesis for this test;
- 18M.2.sl.TZ1.2d.i: Write down the χ2 statistic.
- 18M.2.sl.TZ2.3b.ii: Find the value of q.
- 12M.2.sl.TZ1.2e: Use your graphic display calculator to determine the \(\chi _{calc}^2\) value.
- 11M.2.sl.TZ1.2B.e: A \({\chi ^2}\) test at the \(5\% \) significance level was carried out to determine whether...
- 11M.2.sl.TZ2.1A.d: Use your graphic display calculator to find the \({\chi ^2}\) test statistic for this data.
- 11M.2.sl.TZ2.1A.c: Find the expected frequency for the females studying Spanish.
- 13M.2.sl.TZ1.1a: State the null hypothesis, H0, for the test.
- 07M.1.sl.TZ0.8d: The critical value, at the 5% level of significance, is 9.488. What conclusion can be drawn...
- 07N.2.sl.TZ0.4ii.e: (i) State the number of degrees of freedom available for this calculation. (ii) State his...
- 08M.1.sl.TZ1.5d: State whether or not you will reject the null hypothesis, giving a clear reason for your answer.
- 09N.2.sl.TZ0.4B, c, ii: The calculated value of \({\chi ^2}\) is \(1.367\) and the critical value of \({\chi ^2}\) is...
- 14N.1.sl.TZ0.10d: Minta found that the calculated value of the \({\chi ^2}\) test was 3.576. The critical value...
- 14N.1.sl.TZ0.10b: State the number of degrees of freedom.
- 16M.1.sl.TZ1.10d: From the travellers taking part in the survey, 285 were 61 years or older and 420 preferred...
- 16M.1.sl.TZ2.7c: State the conclusion of the test. Give a reason for your answer.
- 17N.2.sl.TZ0.1f.ii: Write down the \({\chi ^2}\) statistic.
- 18M.2.sl.TZ1.2h: Two flights are chosen at random from those which were slightly delayed. Find the...
- 18M.2.sl.TZ2.3c: Given that P(W > k) = 0.225 , find the value of k.
- 10M.1.sl.TZ2.9a.i: Write down the null hypothesis.
- 10N.2.sl.TZ0.1B.b: Write down the number of degrees of freedom for this test.
- 12N.2.sl.TZ0.4c: The manager of the store wants to determine whether the screen size is independent of gender....
- 12N.2.sl.TZ0.4b: The manager of the store wants to determine whether the screen size is independent of gender....
- 11N.2.sl.TZ0.2d: Write down (i) the Chi-squared calculated value; (ii) the number of degrees of...
- 09M.2.sl.TZ2.2i, f: Is the manufacturer’s claim justified? Give a reason for your answer.
- 13M.2.sl.TZ1.1c: Write down the critical value for the test.
- 13M.1.sl.TZ2.6c: Write down the critical value for this test.
- 13M.1.sl.TZ2.6d: State the conclusion of this test. Give a reason for your decision.
- SPM.1.sl.TZ0.8c: State, with a reason, the conclusion of the test.
- 08M.1.sl.TZ1.5a: Write down the null hypothesis.
- 08M.2.sl.TZ2.2i.c: The market research organization tests the survey data to determine whether the brand of...
- 08M.2.sl.TZ2.2i.g: The market research organization tests the survey data to determine whether the brand of...
- 14M.1.sl.TZ2.8c: The \({\chi ^2}\) critical value is \(7.815\) at the \(5\%\) significance level. State...
- 14M.1.sl.TZ1.4d: State, giving a reason, whether the null hypothesis should be accepted.
- 15M.2.sl.TZ1.1c: Show that the expected frequency of those between the ages of 26 and 40 who oppose the...
- 16M.1.sl.TZ1.10b: Find the number of degrees of freedom.
- 16M.1.sl.TZ1.10c: The critical value of this \(\chi {\,^2}\) test is \(21.026\). Use this information to write...
- 17M.2.sl.TZ2.1g: State the conclusion of this \({\chi ^2}\) test. Give a reason for your answer.
- 17M.2.sl.TZ2.1f: Use your graphic display calculator to find the \({\chi ^2}\) statistic for this data.
- 17M.2.sl.TZ2.1a.iii: If the teacher chooses a response at random, find the probability that it is a satisfactory...
- 18M.2.sl.TZ1.2a: State the alternative hypothesis.
- 12N.2.sl.TZ0.4d: The manager of the store wants to determine whether the screen size is independent of gender....
- 09M.1.sl.TZ1.6a: Find the number of degrees of freedom for the \(\chi^2\) test.
- 11M.2.sl.TZ1.2B.f: A \({\chi ^2}\) test at the \(5\% \) significance level was carried out to determine whether...
- 09M.2.sl.TZ2.2i, c: Write down the value of \(\chi_{calc}^2\).
- 09M.2.sl.TZ2.2i, a: Write down the null and alternative hypotheses for this test.
- 09M.2.sl.TZ2.2i, d: Write down the number of degrees of freedom.
- 08M.1.sl.TZ1.5c: Write down the chi-squared value.
- 08M.2.sl.TZ2.2i.d: The market research organization tests the survey data to determine whether the brand of...
- 09N.2.sl.TZ0.4B, c, iv: The calculated value of \({\chi ^2}\) is \(1.367\) and the critical value of \({\chi ^2}\) is...
- 13N.1.sl.TZ0.8b: Write down the number of degrees of freedom.
- 14M.1.sl.TZ1.4a: State the null hypothesis.
- 15M.1.sl.TZ2.7c: Use your graphic display calculator to find the \(p\)-value for this test.
- 15M.2.sl.TZ1.1a: State (i) \({{\text{H}}_0}\), the null hypothesis for the test; (ii) ...
- 16N.1.sl.TZ0.6b: For this test, write down the \({\chi ^2}\) statistic.
- 16M.1.sl.TZ2.7a: A survey was conducted among a random sample of people about their favourite TV show. People...
- 17M.2.sl.TZ2.1a.ii: If the teacher chooses a response at random, find the probability that it is a satisfactory...
- 17N.2.sl.TZ0.1a: State whether \(N\) is a discrete or a continuous variable.
- 17N.2.sl.TZ0.1b.i: Write down, for \(N\), the modal class;
- 17N.2.sl.TZ0.1c.i: Use your graphic display calculator to estimate the mean of \(N\);
- 18M.2.sl.TZ1.2b: Calculate the expected frequency of flights travelling at most 500 km and arriving slightly...
- 18M.2.sl.TZ1.2d.ii: Write down the associated p-value.
- 18M.2.sl.TZ2.3d.i: For this test state the null hypothesis.
- 10N.2.sl.TZ0.1B.c: Write down the critical value for this test.
- 12N.2.sl.TZ0.4f: The manager of the store wants to determine whether the screen size is independent of gender....
- 12M.2.sl.TZ1.2b: Find the expected value of female footballers.
- 12M.2.sl.TZ1.2c: Write down the number of degrees of freedom.
- 12M.1.sl.TZ2.8c: At the 5 % significance level the \(\chi_{calc}^2\) was found to be 8.73. Write down the...
- 11N.2.sl.TZ0.2c: Pam decides to test her belief using a Chi-squared test at the \(5\% \) level of...
- 09N.2.sl.TZ0.4B, c, i: The calculated value of \({\chi ^2}\) is \(1.367\) and the critical value of \({\chi ^2}\) is...
- 11M.2.sl.TZ1.2B.g: A \({\chi ^2}\) test at the \(5\% \) significance level was carried out to determine whether...
- 09M.2.sl.TZ2.2i, b: For the number of fertilized plants with height greater than 75 cm, show that the expected...
- 11M.2.sl.TZ2.1A.e: State whether Ludmila accepts the null hypothesis. Give a reason for your answer.
- 13M.1.sl.TZ2.6a: Write down the null hypothesis.
- 08N.2.sl.TZ0.3a: Jorge applies a \({\chi ^2}\) test at the \(5\% \) level to investigate whether wearing a...
- 08M.2.sl.TZ2.2i.e: The market research organization tests the survey data to determine whether the brand of...
- 14M.1.sl.TZ1.4b: Write down the number of degrees of freedom.
- 14M.1.sl.TZ1.4c: Write down (i) the \({\chi ^2}\) statistic; (ii) the associated p-value.
- 14N.1.sl.TZ0.10a: State Minta’s null hypothesis.
- 14N.1.sl.TZ0.10c: 150 students showed a preference for a smoothie. Calculate the expected number of female...
- 17N.2.sl.TZ0.1f.i: Write down the \(p\)-value for the test;
- 18M.2.sl.TZ1.2e: State, with a reason, whether you would reject the null hypothesis.
- 10M.1.sl.TZ1.10a: State the null hypothesis, H0, for this test.
- 10N.2.sl.TZ0.1B.f: Decide whether H0 must be accepted. Justify your answer.
- 12N.2.sl.TZ0.4g: The manager of the store wants to determine whether the screen size is independent of gender....
- 12M.2.sl.TZ1.2d: Write down the critical value of \(\chi ^2\), at the 5 % level of significance.
- 12M.2.sl.TZ1.2a: Write down the null hypothesis, H0, for this test.
- 09M.1.sl.TZ1.6b: Write down the null hypothesis for the \(\chi^2\) test.
- 11M.2.sl.TZ2.1A.b: Write down the number of degrees of freedom.
- 11M.2.sl.TZ2.1A.a: State Ludmila’s null hypothesis.
- 07N.2.sl.TZ0.4ii.a: Draw a table with 2 rows and 4 columns of data so that Manuel can perform a chi-squared test.
- 07N.2.sl.TZ0.4ii.c: Find the expected frequency for the number of females who had ‘Comedy’ as their most-watched...
- 08M.1.sl.TZ1.5b: Write down the number of degrees of freedom.
- 14M.1.sl.TZ2.8b: Find the \({\chi ^2}\) statistic.
- 13N.1.sl.TZ0.8d: The critical value, at the \(5\%\) significance level, is \(7.815\). State, giving a reason,...
- 15M.2.sl.TZ1.1e: Determine, giving a reason, whether \({{\text{H}}_0}\) should be accepted.
- 17M.1.sl.TZ1.6a: Write down the value of \(x\).
- 17M.1.sl.TZ1.6d: State the conclusion for this test. Give a reason for your answer.
- 17M.2.sl.TZ2.1e: Write down the number of degrees of freedom for this test.
- 17N.2.sl.TZ0.1g: State the result of the test. Give a reason for your answer.
- 18M.2.sl.TZ1.2c: Write down the number of degrees of freedom.
- 18M.2.sl.TZ2.3b.i: Sketch a normal curve to represent this probability.
- 18M.2.sl.TZ2.3e: State a conclusion for this test. Justify your answer.