A psychologist wanted to investigate whether mindfulness meditation affects systolic blood pressure in high-stress corporate employees. Previous research on the effects of meditation on cardiovascular health had consistently shown that mindfulness training reduces systolic blood pressure.

The psychologist decided to use an independent measures design to investigate the effects of meditation on blood pressure in 40 office workers who scored highly on a pre-screened stress index.

• Condition A: 20 participants were required to complete a formal 15-minute guided mindfulness meditation session every morning before beginning work for a period of two weeks.
• Condition B: 20 participants spent 15 minutes sitting quietly reading light-hearted news articles during the same morning period for two weeks.

At the end of the two weeks, the systolic blood pressure (measured in mmHg) of each participant was recorded.

Which of the following types of hypothesis is not appropriate for the psychologist to use in their study?