1.
The following is a set of measurements:
11.0, 11.4, 12.3, 10.5, 11.6, 11.2, 11.8, 11.1, 11.2, 11.3, 11.5
The mean value is closest to:
2.
The lifetime of Last Forever car batteries is approximately normally distributed with a mean of 24 months and a standard deviation of three months. If 2000 batteries are sold, the number expected to last less than 15 months is closest to:
3.
The lifetime of Last Forever car batteries is approximately normally distributed with a mean of 24 months and a standard deviation of three months. The percentage of batteries that can be expected to last less than 30 months is:
4.
The lifetime of Last Forever car batteries is approximately normally distributed with a mean of 24 months and a standard deviation of three months. The percentage of batteries that can be expected to last less than 21 months is:
5.
The lifetime of Last Forever car batteries is approximately normally distributed with a mean of 24 months and a standard deviation of three months. The percentage of batteries that can be expected to last between 18 and 30 months is:
6.
The lifetime of Last Forever car batteries is approximately normally distributed with a mean of 24 months and a standard deviation of three months. The percentage of batteries that can be expected to last more than 24 months is:
7.
In a normal distribution, approximately 16% of values lie:
A.
Within one Standard Deviation of the mean
B.
Within two Standard Deviations of the mean
C.
Within two Standard Deviations of the mean
D.
More than one Standard Deviation above the mean
E.
More than two Standard Deviations below the mean
F.
8.
In a normal distribution, approximately 95% of values lie:
A.
Within one Standard Deviation of the mean
B.
Within two Standard Deviations of the mean
C.
Within three Standard Deviations of the mean
D.
More than one Standard Deviation above the mean
E.
More than two Standard Deviations below the mean
F.
9.
A student’s standardised score on a test was –2. The mean score on the test was 20 marks with a standard deviation of 3. Her actual mark on the test was:
10.
A student’s mark on a test is 60. The mean mark for their class is 75 and the standard deviation is 6. Their standard score is:-
11.
It would not be appropriate to determine the mean and standard deviation of a group of women’s:
A.
B.
C.
D.
E.
Time spent on leisure activities
F.
12.
The histogram above shows the distribution of the amount spent on gambling by a large sample of gamblers.
For this distribution, the mean would be:
A.
B.
Approximately equal to the median
C.
D.
E.
F.
13.
For this set of test marks:
20, 21, 13, 15, 16, 24, 17
the actual value of the standard deviation, correct to one decimal place, is:
14.
For this set of test marks:
20, 21, 13, 15, 16, 24, 17
an estimate of the standard deviation (based on the range) is
15.
At Cassie’s school the students are given both a mark and a standardised score for each test they sit. In some recent revision tests, Cassie got the results shown. Assuming the marks are approximately normally distributed, use the standardised scores to decide which of the following statements is not true.
A.
Cassie’s score in Further Maths is close to the average score for that subject.
B.
Cassie’s score in English placed her in the top 2.5% of students sitting the test.
C.
Cassie’s score in Psychology placed her in the bottom 16% of students sitting the test.
D.
Cassie scored above average in all subjects.
E.
More than half the class had a higher mark in Biology than Cassie.
F.