We have
And we want
Another way to read it is
It should be clear that the solution is
Answer:
The 90% confidence interval for the true mean natural gas bill for homes in the 19808 zip code area in February is between $292.48 and $331.32
Step-by-step explanation:
We have the standard deviation for the sample, which means that the t-distribution is used to solve this question.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 21 - 1 = 20
90% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 20 degrees of freedom(y-axis) and a confidence level of . So we have T = 1.7247
The margin of error is:
In which s is the standard deviation of the sample and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 311.9 - 19.42 = $292.48
The upper end of the interval is the sample mean added to M. So it is 311.9 + 19.42 = $331.32
The 90% confidence interval for the true mean natural gas bill for homes in the 19808 zip code area in February is between $292.48 and $331.32
Answer:
3
Step-by-step explanation:
25=4x+3x
25=7x
25/7=3.5
25=4(3.5)+3(3.5)
25=14+10.5
10.5/3=3.5
he bought 3 candy bars
Yes, there are many possible answers. An equation that can model your situation is:
4a+4b=75, with a being the amount of adult tickets sold, and b being the amount of children’s tickets sold.
Because both tickets cost 4 dollars, you would multiply the amount of tickets sold, by the price (in dollars) of the ticket.
So, you can find possible answers by substituting the amount of adult tickets sold. Say, 4 adults bought tickets. You could then substitute a for 4. So the equation would look like this.
4(4)+4b=75
16 + 4b = 75
4b = 75 - 16
4b = 59
Divide each side by four
B = 14.75
The reason you got a decimal number is because 75 cannot be divided by 4 evenly. So, in this context, you could say that 15 children bought tickets. One child had an issue, and Lisa gave them a 25% discount. This would explain why there are only 75 dollars worth in tickets. I hope I helped, this is my first question I have ever answered so I’m not entirely sure if this was helpful or not. Hope you figure this out!