Answer:
He received 10 dimes and 15 quarters.
Step-by-step explanation:
Dimes = $0.10
Quarters = $0.25
Variable x = dimes
Variable y = quarters
Create a pair of linear equations:
0.10x + 0.25y = 4.75
x + y = 25
Isolate any variable, using an equation of your choice:
x + y = 25
x = 25 - y
Plug in this new value of x into the other equation:
0.10(25 - y) + 0.25y = 4.75
Use the distributive property:
2.5 - 0.10y + 0.25y = 4.75
Combine like terms:
2.5 + 0.15y = 4.75
Isolate variable y:
0.15y = 2.25
y = 15
Plug in the value of y into any equation:
x + y = 25
x + 15 = 25
Isolate variable x:
x = 10
Answer:
2
Step-by-step explanation:
5% = 0.05
0.05 * 35 = 1.75
So, roughly 2 people voted for it.
Answer:
Choice B
Step-by-step explanation:
7.1×10⁵ = 710,000
Answer:
Explained below.
Step-by-step explanation:
(1)
The hypothesis can be defined as follows:
<em>H</em>₀: The Speedy Oil Change will change the oil in customers’ cars in more than 30 minutes on average, i.e. <em>μ</em> > 30.
<em>H</em>ₐ: The Speedy Oil Change will change the oil in customers’ cars in less than 30 minutes on average, i.e. <em>μ</em> ≤ 30.
(2)
Use Excel to compute the sample mean and standard deviation as follows:

Compute the test statistic as follows:

The degrees of freedom is:
df = n - 1
= 36 - 1
= 35
Compute the p-value as follows:

(3)
The <em>p</em>-value = 0.0006 is very small.
The null hypothesis will be rejected at any of the commonly used significance level.
(4)
There is sufficient evidence to support the claim that the Speedy Oil Change will change the oil in customers’ cars in less than 30 minutes on average.