Answer:
No, Matt did not solve the equation correctly
Correct Answer: x = 8
Step-by-step explanation:
4(x + 2) = 30
Step 1: Distribute
4x + 2 = 30 
This is his mistake, he should completely distribute 4
to x and 2
Step 2: Subtract 2 from both sides/Isolate x
4x = 28 This part is done correctly, but wrong because of Step 1
Step 3: Divide both sides by 4
x = 7 This is correct, but again, he messed up on Step 1
<h3>
Let's find the correct answer to this equation:</h3><h3>4(x +2) = 30</h3>
Step 1: Distribute
Remember to distribute 4 to all terms in the parenthesis.
4(x + 2) = 4(x) + 4(2)
= 4x + 8
4x + 8 = 30
Step 2: Subtract 8 from both sides/Isolate x
Move all the terms that do not belong to x to the other side. We can do this by subtracting 8 from both sides (opposite operation of adding 8)
4x + 8 = 30
4x = 30 - 8
4x = 32
Step 3: Divide both sides by 4/Isolate x
Now we want x by itself. Since x is being multiplied by 4, we have to use the opposite operation, dividing by 4, to have x on one side by itself
4x = 32
4(x) = 32
x = 32 ÷ 4
x = 8
-Chetan K
Complete question:
He amount of time that a customer spends waiting at an airport check-in counter is a random variable with mean 8.3 minutes and standard deviation 1.4 minutes. Suppose that a random sample of n equals 47 customers is observed. Find the probability that the average time waiting in line for these customers is
a) less than 8 minutes
b) between 8 and 9 minutes
c) less than 7.5 minutes
Answer:
a) 0.0708
b) 0.9291
c) 0.0000
Step-by-step explanation:
Given:
n = 47
u = 8.3 mins
s.d = 1.4 mins
a) Less than 8 minutes:
P(X' < 8) = P(Z< - 1.47)
Using the normal distribution table:
NORMSDIST(-1.47)
= 0.0708
b) between 8 and 9 minutes:
P(8< X' <9) =![[\frac{8-8.3}{1.4/ \sqrt{47}}< \frac{X'-u}{s.d/ \sqrt{n}} < \frac{9-8.3}{1.4/ \sqrt{47}}]](https://tex.z-dn.net/?f=%20%5B%5Cfrac%7B8-8.3%7D%7B1.4%2F%20%5Csqrt%7B47%7D%7D%3C%20%5Cfrac%7BX%27-u%7D%7Bs.d%2F%20%5Csqrt%7Bn%7D%7D%20%3C%20%5Cfrac%7B9-8.3%7D%7B1.4%2F%20%5Csqrt%7B47%7D%7D%5D)
= P(-1.47 <Z< 6.366)
= P( Z< 6.366) - P(Z< -1.47)
Using normal distribution table,
0.9999 - 0.0708
= 0.9291
c) Less than 7.5 minutes:
P(X'<7.5) = ![P [Z< \frac{7.5-8.3}{1.4/ \sqrt{47}}]](https://tex.z-dn.net/?f=%20P%20%5BZ%3C%20%5Cfrac%7B7.5-8.3%7D%7B1.4%2F%20%5Csqrt%7B47%7D%7D%5D%20)
P(X' < 7.5) = P(Z< -3.92)
NORMSDIST (-3.92)
= 0.0000
Answer:
x = 4 , y = 2
Step-by-step explanation:
Using the sine / tangent ratios in the right triangle and the exact values
sin60° = 
and tan60° = 
, then
sin60° = 
= 
= ( cross- multiply )
x = 4 ( divide both sides by )
x = 4
and
tan60° = 
= 
= ( multiply both sides by y )
y = 2 ( divide both sides by )
y = 2
No, because she only has $11.23 left.
