Final answer:
The x intervals given are converted to z intervals by subtracting the mean and dividing by the standard deviation. For an RBC count with mean 4.8 million/mm³ and standard deviation 0.3, the intervals 4.5, x<4.2, and 4.0 correspond to z = -1, z < -2, and z < -2, respectively.
Step-by-step explanation:
To convert the given x intervals to z intervals for a red blood cell (RBC) count with a mean of 4.8 million per cubic millimeter and a standard deviation σ = 0.3, we use the z-score formula: z = (x - μ) / σ, where x is the value in the x interval, μ is the mean, and σ is the standard deviation.
- For x = 4.5: z = (4.5 - 4.8) / 0.3 = -1
- For x < 4.2: z < (4.2 - 4.8) / 0.3 = -2
- For x = 4.0: z = (4.0 - 4.8) / 0.3 = -2.67, which is less than -2
Therefore, the corresponding z intervals are:
- For the interval 4.5: z = -1
- For the interval x < 4.2: z < -2
- For the interval 4.0: z < -2 (as it is less than -2)