This paper presents a new measurement of the fluctuation parameter \( F \) in the context of the Macquart relation, which describes the correlation between the dispersion measure (DM) of fast radio bursts (FRBs) and their host galaxy redshifts. The variance of the DM distribution in the cosmic web, parameterized by \( F \), is sensitive to the distribution of baryons in the intergalactic medium (IGM). The authors use a forward model to analyze 78 FRBs, 21 of which have been localized to host galaxies. They simultaneously fit for the Hubble constant \( H_0 \) and the DM distribution due to the FRB host galaxies. The results show that \( F \) is degenerate with \( H_0 \), and by using a uniform prior on \( H_0 \), they measure \( \log_{10} F > -0.86 \) at the 3\(\sigma\) confidence level. Additionally, they constrain \( H_0 = 85.3^{+9.4}_{-8.1} \) km s\(^{-1}\) Mpc\(^{-1}\). The constraint on \( F \) improves by a factor of \(\sim 2\) when using a synthetic sample of 100 localized FRBs. The measured \( F \) values are in agreement with simulations (IllustrisTNG) between redshifts \( 0.4 < z < 2.0 \), but simulations underpredict \( F \) at \( z < 0.4 \) due to the rapidly changing extragalactic DM excess distribution at low redshifts. The study highlights the potential of FRBs as a new observable for constraining cosmic feedback strength and the distribution of baryons in the IGM.This paper presents a new measurement of the fluctuation parameter \( F \) in the context of the Macquart relation, which describes the correlation between the dispersion measure (DM) of fast radio bursts (FRBs) and their host galaxy redshifts. The variance of the DM distribution in the cosmic web, parameterized by \( F \), is sensitive to the distribution of baryons in the intergalactic medium (IGM). The authors use a forward model to analyze 78 FRBs, 21 of which have been localized to host galaxies. They simultaneously fit for the Hubble constant \( H_0 \) and the DM distribution due to the FRB host galaxies. The results show that \( F \) is degenerate with \( H_0 \), and by using a uniform prior on \( H_0 \), they measure \( \log_{10} F > -0.86 \) at the 3\(\sigma\) confidence level. Additionally, they constrain \( H_0 = 85.3^{+9.4}_{-8.1} \) km s\(^{-1}\) Mpc\(^{-1}\). The constraint on \( F \) improves by a factor of \(\sim 2\) when using a synthetic sample of 100 localized FRBs. The measured \( F \) values are in agreement with simulations (IllustrisTNG) between redshifts \( 0.4 < z < 2.0 \), but simulations underpredict \( F \) at \( z < 0.4 \) due to the rapidly changing extragalactic DM excess distribution at low redshifts. The study highlights the potential of FRBs as a new observable for constraining cosmic feedback strength and the distribution of baryons in the IGM.