Brass is made from a mixture of copper and other elements. A mixture that is 80% copper is combined with a mixture that is 60%, resulting in 100 pounds that is 65% copper. Which equation can be used to find x the amount of 60% mixture used to create the 65% mixture?
0.8 (100-x) + 0.6x = 100(0.65)
0.6(100 -x) + 0.8x = 100(0.65)
0.8(100) + 0.6x =0.65(100 - x)
0.6(x) + 0.8(100 +x) =0.65

Recall that the owner of a local health food store recently started a new ad campaign to attract more business and wants to know if average daily sales have increased. historically average daily sales were approximately $2,700. the upper bound of the 95% range of likely sample means for this one-sided test is approximately $2,843.44. if the owner took a random sample of forty-five days and found that daily average sales were now $2,984, what can she conclude at the 95% confidence level?

Select all the statements that apply to this figure

The mean average cost of standard room per night at a hostel is ? 20.60. therefore, how much does a standard room cost per night at night-time rest days?