Answer:
He must work 52 days to pay for a single ticket.
Step-by-step explanation:
This question can be solved using proportions.
Per hour:
Joel earns $7.25 per hour, 20% of which is deducted for taxes. So without taxes, in each hour, he earns 100%-20% of 80% of this, so 0.8*7.25 = $5.8.
Per day:
He works 9 a.m. to 5 p.m. each day, so 8 hours a day.
For each hour, he earns $5.8.
So in a day, he makes 8*5.8 = $46.4
How many days he must work:
The ticket costs $2400.
He makes $46.4 a day.
So, to buy a ticket, he needs to work:
2400/46.4 = 51.7 days
Rounding up
He must work 52 days to pay for a single ticket.
Let's call our estimate x. It will be the average of n IQ scores. Our average won't usually exactly equal the mean 97. But if we repeated averages over different sets of tests, the mean of our estimate the average would be the same as the mean of a single test,
μ = 97
Variances add, so the standard deviations add in quadrature, like the Pythagorean Theorem in n dimensions. This means the standard deviation of the average x is
σ = 17/√n
We want to be 95% certain
97 - 5 ≤ x ≤ 97 + 5
By the 68-95-99.7 rule, 95% certain means within two standard deviations. That means we're 95% sure that
μ - 2σ ≤ x ≤ μ + 2σ
Comparing to what we want, that's means we have to solve
2σ = 5
2 (17/√n) = 5
√n = 2 (17/5)
n = (34/5)² = 46.24
We better round up.
Answer: We need a sample size of 47 to be 95% certain of being within 5 points of the mean
Step-by-step explanation:
- (-2)4 = -8
- -8 +(-10)= -18
- -18 divide by -5= 18/5
Answer:
Step-by-step explanation:
y-5/x+1 = -3/7
7(y-5)=-3(x+1)
7y-35=-3x-3
7y+3x-32=0
Answer:
<u>The answer is 5 set of curtains and it remains 6 yards of fabric.</u>
Step-by-step explanation:
Let's calculate the number of sets of curtains that Ruby can make with the 46 yards of fabric.
Number of sets of curtains = 46/8
Number of sets of curtains = 5 and it remains 6 yards
<u>The answer is 5 set of curtains and it remains 6 yards of fabric.</u>