Answer:
Step-by-step explanation:
To find out the sales tax rate, we divide the sales tax by the cost of the item. This will give us what percent of the cost of the item the sales tax is equal to.
So, 20.4 divided by 340 = 0.06
To convert to percent, we multiply 0.06 by 100=6. Therefore, the sales tax rate is 6%.
Check:
340 times 0.06 (the sales tax rate) is 20.4 (the sales tax).
10% is 7 dollars so 20% is 14 and have of 7 is 3.5 so it's 17.50
Answer: She started with $160.
It will take 6 weeks before she has less than half of what she originally invested.
Step-by-step explanation:
If her money is decreasing in value by 11% each week, it means that the rate at which it is decreasing is exponential.
We would apply the formula for exponential decay which is expressed as
A = P(1 - r)^t
Where
A represents the value of the investment after t weeks.
t represents the number of weeks.
P represents the initial value of the investment.
r represents rate of depreciation.
From the information given,
A = $142.40
r = 11% = 11/100 = 0.11
t = 1
Therefore
142.40 = P(1 - 0.11)^1
142.40 = P(0.89)
P = 142.4/0.89
P = 160
For her to have half of what she invested originally, then
80 = 160(0.89)^t
80/160 = (0.89)^t
0.5 = (0.89)^t
Taking log of both sides to base 10
Log 0.5 = log0.89^t = tlog0.89
- 0.3010 = - 0.051t
t = - 0.3010/- 0.051
t = 5.9
Approximately 6 weeks
Answer:
t = -1.428
Step-by-step explanation:
Average blood pressure among people with high responsibility jobs = u = 140 mm
Number of people sampled for the study = n = 51
Average blood pressure of the sample = x = 139 mm
Standard deviation of the sample = s = 5 mm
The claim is that practicing yoga decreases the blood pressure. So we have to test that after practicing yoga, the average blood pressure will be lesser than 140. Based on this we can formulate the null and alternate hypothesis as:
Null Hypothesis: 
Alternate Hypothesis: 
Since population standard deviation is not known, we cannot use z-distribution for this test. We are given the value of sample standard deviation, so t-test will be used for this case.
Test statistic is calculated as:
Using the values in this formula gives us:
Therefore, the value of test statistic is -1.428
Answer:
y= 143°
x= 37°
Step-by-step explanation:
y is 143° cause they are the same thing just on the other side.
x us 37°cause 180-143 is 37.
