Answer:
Step-by-step explanation:
28=8+5x
20=5x
=4
four is your answer
Step-by-step explanation:
21 is the answer cause if she sold 4 already thats equal 25 boxes of cookies
Answer:
a) Increase the sample size
Step-by-step explanation:
Given that a 95% confidence interval for μ turns out to be (1,000, 2,100)
The confidence interval is formed as
Margin of error = critical value * std dev/sqrt of sample size
Hence for the same confidence level, we cannot change critical value.
The only available ways are either to decrease std deviation or increase the sample size to make it narrower.
If confidence level becomes higher, then confidence interval would be wider.
Here out of four options the correct option is
a) Increase the sample size
Trumpet = $174 Clarinet = $149 Violin = $89 Let's write some equations to express what we know. 2t + 3c + 5v = 1240 3t + 1c + 4v = 1027 5t + 7c + 2v = 2091 So we have 3 unknowns and 3 equations. The 2t and 3t are rather interesting in the 1st 2 equations since the 3rd equation has 5t. So if we subtract the 1st and 2nd equations, we can cancel out the t values. So 5t + 7c + 2v = 2091 -( 3t + 1c + 4v = 1027) = 2t + 6c - 2v = 1064 -(2t + 3c + 5v = 1240) = 3c - 7v = -176 Now we can express c in terms of v. 3c - 7v = -176 3c = 7v - 176 c = (7/3)v - 58 2/3 Substitute the expression (7/3)v - 58 2/3 for c in the expression 2t + 3c + 5v = 1240 giving 2t + 3((7/3)v - 58 2/3) + 5v = 1240 and solve for t, first distribute the 3 2t + 7v - 176 + 5v = 1240 Merge the v terms 2t + 12v - 176 = 1240 Add 176 to both sides 2t + 12v = 1240 + 176 = 1416 Subtract 12 v from both sides 2t = 1416 - 12v Divide both sides by 2 t = 708 - 6v Now substitute both 708 - 6v for t and (7/3)v - 58 2/3 for c in 3t + 1c + 4v = 1027 and solve for v 3t + 1c + 4v = 1027 3(708 - 6v) + (7/3)v - 58 2/3 + 4v = 1027 Distribute the 3 3(708 - 6v) + (7/3)v - 58 2/3 + 4v = 1027 2124 - 18v + (7/3)v - 58 2/3 + 4v = 1027 Combine terms 2065 1/3 - (11 2/3)v = 1027 Subtract 2065 1/3 from both sides -(11 2/3)v = 1027 - 2065 1/3 = -1038 1/3 Divide both sides by -11 2/3 v = 89 So we know the violins cost $89 each. Plugging that value into the formula t = 708 - 6v which we created earlier t = 708 - 6v t = 708 - 6 * 89 = 708 - 534 = 174 So we know that a trumpet costs $174 Now plug the price of a violin into the formula c = (7/3)v - 58 2/3 to get the cost of a clarinet. c = (7/3)v - 58 2/3 c = (7/3)89 - 58 2/3 = 207 2/3 - 58 2/3 = 149 And a clarinet is $149 Let's verify 2t + 3c + 5v = 2*174 + 3*149 + 5*89 = 348 + 447 + 445 = 1240 3t + 1c + 4v = 3*174 + 1*149 + 4*89 = 522 + 149 + 356 = 1027 5t + 7c + 2v = 5*174 + 7*149 + 2*89 = 870 + 1043 + 178 = 2091 All the expressions match what was given, so the prices are Trumpet = $174 Clarinet = $149 Violin = $89
The difference in the proportions of both surveys goes from a maximum of 12.57% to a minimum of 4.76%.
Given that a survey found that in a sample of 75 families, 26 owned dogs, while a survey done 15 years ago found that in a sample of 60 families, 26 owned dogs, to find the 95% confidence intervals of the true difference in the proportions, the following calculation must be performed:
- 75 = 100
- 26 = X
- 26 x 100/75 = X
- 34.66 = X
- 34.66 x 0.95 = 32.93
- 34.66 x 1.05 = 36.40
-
60 = 100
- 26 = X
- 26 x 100/60 = X
- 43.33 = X
- 43.33 x 0.95 = 41.16
- 43.33 x 1.05 = 45.50
-
45.50 - 32.93 = 12.57
- 41.16 - 36.40 = 4.76
Therefore, the difference in the proportions of both surveys goes from a maximum of 12.57% to a minimum of 4.76%.
Learn more about maths in brainly.com/question/25989509
