Answer:
865
Step-by-step explanation:
We have that in 95% confidence level the value of z has a value of 1.96. This can be confirmed in the attached image of the normal distribution.
Now we have the following formula:
n = [z / E] ^ 2 * (p * q)
where n is the sample size, which is what we want to calculate, "E" is the error that is 2% or 0.02. "p" is the probability they give us, 5 out of 50, is the same as 1 out of 10, that is 0.1. "q" is the complement of p, that is, 1 - 0.1 = 0.9, that is, the value of q is 0.9.
Replacing these values we are left with:
n = [1.96 / 0.02] ^ 2 * [(0.1) * (0.9)]
n = 864.36
865 by rounding to the largest number.
Add 3 to both sides so that the equation becomes -2x^2 + 5x + 5 = 0.
To find the solutions to this equation, we can apply the quadratic formula. This quadratic formula solves equations of the form ax^2 + bx + c = 0
x = [ -b ± √(b^2 - 4ac) ] / (2a)
x = [ -5 ± √(5^2 - 4(-2)(5)) ] / ( 2(-2) )
x = [-5 ± √(25 - (-40) ) ] / ( -4 )
x = [-5 ± √(65) ] / ( -4)
x = [-5 ± sqrt(65) ] / ( -4 )
x = 5/4 ± -sqrt(65)/4
The answers are 5/4 + sqrt(65)/4 and 5/4 - sqrt(65)/4..
Answer:
Wilton found 10 dimes while cleaning his father's truck.
Step-by-step explanation:
Given that:
Total amount collected = $8.50 = 8.50*100 = 850 cents
Let,
x be the number of dimes
y be the number of quarters
According to given statement,
10x+25y=850 Eqn 1
y = 3x Eqn 2
Putting y=3x in Eqn 1
Dividing both sides by 85
As x represents dimes, therefore, number of dimes is 10.
Hence,
Wilton found 10 dimes while cleaning his father's truck.
Answer:
Step-by-step explanation:
for 1st week=1 ¢
for 2nd week= 2¢
for 3rd week= 4¢
for 4th week=8¢
for 5th week=16¢
for 6th week=32¢
for 7th week=64¢
for 8th week=64+64=128¢
for 9th week= 128+128=256¢
for 10th week= 256+256=512¢
.: he saved a total of
1+2+4+8+16+32+64+128+256+512=1023¢
1023¢=1023/100=$10.23
