7. Write the expression in standard form and classify the polynomial

9x – 5 + 8x^2

d. For college students, music is associated with statistically significant improvements in concentration as measured by time to complete a simple word puzzle.

Step-by-step explanation:

Hello!

The variable of interest is

Xd: Difference between the time that takes a person to complete a simple word puzzle without music and with music.

The parameter of interest is the mean difference between the two times.

The claim is that music increases the concentration and thus decreases the time it takes a person to resolve the word puzzle. If so then the mean difference between the two times should be positive, μ > 0.

H₀: μ = 0

H₁: μ > 0

α: 0.05

p-value= 0.038

The decision rule using the p-value approach is:

If the p-value ≤ α, then you reject the null hypothesis.

If the p-value > α, then you don't reject the null hypothesis.

The p-value is less than the level of significance, so the decision is to reject the null hypothesis, then the population mean of the difference between the time it takes a person resolve a puzzle without music and the time it takes a person resolve the puzzle with music is greater than zero. You can conclude that music increases concentration.

I hope this helps!