Answer:
3500 tons
Step-by-step explanation:
The Greenpoint factory produced 2/5 of the bricks that the Consolidate Brick Company produced in 1991.
Let the amount of bricks produced by the Greenpoint factory be g and the amount of bricks produced by the Consolidated brick company be c.
Therefore:
g = 2/5 * c = 2c/5
That year, the Greenpoint factory produced 1400 tons of bricks. This implies that:
1400 = 2c/5
To find the amount that the Consolidated Brick Company produced, solve for c:
1400 = 2c/5
1400 * 5 = 2c
7000 = 2c
c = 7000 / 2 = 3500 tons
The Consolidated Brick Company had a total production output of 3500 tons in 1991.
A 99% confidence interval for the population mean of high school students that take the bus to school every day is b) ci=(44.34%, 54.43%)
We need to find the 99% confidence interval for the population mean of high school students that take the bus to school everyday
A confidence interval is a range of estimates for an unknown parameter. The confidence interval is calculated at the specified confidence level; the most common is the 95% confidence level, but sometimes other levels are used, such as 90% or 99%.
The confidence interval of proportions is given by:
π ± z √(π (1-π) /n)
π is the sample proportion.
z is the critical value.
n is the sample size.
For 99% confidence interval the value of z is 2.58
π = 321/650
The confidence interval is given by
=321/650 ± 2.58 √( (321/650) × [ 1 - (321/650) ] ÷ 650)
= (0.493846 ± 0.050594)
=(0.4434 , 0.5443)
=(44.34 % , 54.43 %)
Hence a 99% confidence interval for the population mean of high school students that take the bus to school every day is ci=(44.34%, 54.43%)
<u>Learn more about confidence interval:</u>
brainly.com/question/28052710
# SPJ4
Answer:
240 seventh graders passed
Step-by-step explanation:
300 x 0.8 = 240
Answer:
24 g
Step-by-step explanation:
We first find the mass of 24 % alcohol in 400 g of hand sanitizer. Let x be the mass of alcohol. So, x/400 × 100 % = 24 %
x/400 = 0.24
x = 0.24 × 400
= 96 g
The mass of the other chemicals is thus 400 g - 96 g = 304 g
We now find the mass of 30 % alcohol in 400 g of hand sanitizer. Let y be the mass of alcohol. So, y/400 × 100 % = 30 %
y/400 = 0.30
y = 0.30 × 400
= 120 g
The mass of the other chemicals is thus 400 g - 120 g = 280 g
The mass of other chemicals that needs to be evaporated is thus 304 g - 280 g = 24 g
