The relative humidity would be % if the actual water vapor in the air was 4 grams per cubic meter, the air's capacity to hold water vapor was 8 grams per cubic meter and the dewpoint temperature was ~ 53 degrees fahrenheit.

50%

Explanation:

Humidity is the amount water vapor present in the atmosphere.

Relative humidity is defined as the ratio of partial water vapor present in air to the actual water vapor at a particular temperature. It is expressed in percentage and the higher the percentage RH, the more the saturated water vapor present in the atmosphere and vice versa.

It is expressed mathematically as shown;

RH = actual water vapor in air/saturated water vapor × 100%

If the actual water vapor in the air was 4 grams per cubic meter and the air's capacity to hold water vapor was 8 grams per cubic meter

Actual water vapor = 4g/cm³

Air's water capacity (saturated water vapor) = 8g/cm³

RH = 4/8×100

RH = 50%

spectral lines lyman is one set

speed of light in vacuum is 300,000 km/s

speed of light in other mediums is given by the expression v = c/n, where c is the speed of light in vacuum and n is the refractive index of medium.

for the first medium v = 200,000 km/s

  so, refractive index of medium = 300000/200000 = 1.5

    1.5 refractive index is usually for glass. so first medium is glass.

for the second medium v = 250,00 km/s

so, refractive index of medium = 300000/250000 = 1.2

    1.2 refractive index is usually for water. so second medium is water.

for the third medium v = 0 km/s

so, refractive index of medium = 300000/0 = ∞

    ∞ refractive index is usually for opaque mediums. so third medium is opaque medium.