Can you me with 4? can you give me a rule to follow when naming these?

2,2 dimethyl propane

Step-by-step explanation:

To name such an organic compound, first identify the longest carbon chain in the provided table, the fourth compound, its longest carbon chain has three carbon atoms thus, the prefix prop-

Then we find the other substituents attached to the carbon chain. In the given compound it has two methyl (CH₃) groups attached to the second carbon atom.

thus 2,2 since there are two attached.

The score corresponding to the random variable x is
z = (x -  μ)/σ

given:
μ = 82.4, population mean
σ = 3.3, populaton standard deviation.

we want to determine the percentage  of scores between 75.8 and 89.
for x₁ = 75..8, the z-score is
z₁ = (75.8 - 82.4)/3.3 = -2 (2 std. deviations to the left of the mean)

for x₂ = 89, the z-score is
z₂ = (89 - 82.4)/3.3 = 2 (2 std. deviations to the right of the mean)

from standard tables,
p(z < = z1) = 0.02275
p(z < = 2) = 0.9772

therefore,
p(75. < x < 89) = 0.9772 - 0.02275 = 0.9544 = 95.4%
this result is correct, because the bell curve contains about 95% of the total area within 2 standard deviatins to the lest and to the right of the mean.

answer: 95.4%