Which distribution is described as a symmetrical bell-shaped curve?

Which distribution is described as a symmetrical bell-shaped curve?

• A. Normal distribution
• B. Skewed distribution
• C. Uniform distribution
• D. Bimodal distribution

Answer: (A)

The normal distribution is described as a symmetrical bell-shaped curve. It is centered at the mean and mirrored on both sides, with a single peak at the mean and tails that taper smoothly toward zero in both directions. This unimodal, symmetric shape is why it’s often used as the default model in statistics—it captures many natural measurements and, thanks to the Central Limit Theorem, sums of independent factors tend to this form. The standard normal distribution (mean 0, standard deviation 1) is a convenient reference that lets us compute probabilities across different scales using z-scores. Other forms mentioned—skewed (asymmetric), uniform (flat across its range), and bimodal (two peaks)—do not share this symmetric bell shape, reinforcing why the described curve is characteristic of the normal distribution.

The normal distribution is described as a symmetrical bell-shaped curve. It is centered at the mean and mirrored on both sides, with a single peak at the mean and tails that taper smoothly toward zero in both directions. This unimodal, symmetric shape is why it’s often used as the default model in statistics—it captures many natural measurements and, thanks to the Central Limit Theorem, sums of independent factors tend to this form. The standard normal distribution (mean 0, standard deviation 1) is a convenient reference that lets us compute probabilities across different scales using z-scores. Other forms mentioned—skewed (asymmetric), uniform (flat across its range), and bimodal (two peaks)—do not share this symmetric bell shape, reinforcing why the described curve is characteristic of the normal distribution.