Answer:
A C D E F
Step-by-step explanation:
Might be wrong
When the concentration of a solution is expressed in weight percentages, that is just equal to the mass of solute over the mass of the total solution. For a solution weighing 210 grams, 5% of it is salt. That is equal to
210*0.05= 10.5 g salt
The rest of the amount, determined by difference, is the amount of solvent which is water.
water = 210-10.5 = 199.5 g salt
To solve for the new concentration, you add up 15 g to the already existing 10.5 g of salt in the solution. The water, on the other hand, remains constant.
Concentration = (15+10.5)/(210+15) = 0.1133 or 11.33%
Answer:
Step-by-step explanation:
Given given that
- Lower confidence interval = 7.1
- Upper confidence interval = 7.5
- As such, We are 95% confident that it's somewhere between 7.1 and 7.5 hours per night
Average value = LCI + UCI /2 = 7.1 + 7.5 / 2
= 7.3hours per night, so we are 95% confident that it's somewhere between 7.1 and 7.5 hours per night which is eventually 7.3hrs per night.