Answer:
69 styles
Step-by-step explanation:
75%= 3/4
92/4= 23 (1/4)
23x3= 69
P=$24038.60 has to be invested to have $45000 after 19 years
Answer:
B) variables
Step-by-step explanation:
Answer:
17. Scale Factor is 3:1
18. Scale Factor is 1:3
Step-by-step explanation:
Scale Factor: In two similar shapes, the ratio of their corresponding sides is called scale factor.
17. Give the scale factor of Figure A to Figure B
Figure A has sides:
Hypotenuse = 15
Perpendicular = 12
Base = 9
Figure B has sides:
Hypotenuse = 5
Perpendicular = 4
Base = 3
So, if we divide all sides of figure A by 3 we get Figure B
So, Figure A : Figure B
3:1
18. Give the scale factor of Figure B to Figure A
Figure B has sides:
Hypotenuse = 5
Perpendicular = 4
Base = 3
Figure A has sides:
Hypotenuse = 15
Perpendicular = 12
Base = 9
If we multiply 3 with the sides of Figure B we can get the sides of Figure A.
So scale factor is 3.
So, Figure B : Figure A
1:3
Let's call our estimate x. It will be the average of n IQ scores. Our average won't usually exactly equal the mean 97. But if we repeated averages over different sets of tests, the mean of our estimate the average would be the same as the mean of a single test,
μ = 97
Variances add, so the standard deviations add in quadrature, like the Pythagorean Theorem in n dimensions. This means the standard deviation of the average x is
σ = 17/√n
We want to be 95% certain
97 - 5 ≤ x ≤ 97 + 5
By the 68-95-99.7 rule, 95% certain means within two standard deviations. That means we're 95% sure that
μ - 2σ ≤ x ≤ μ + 2σ
Comparing to what we want, that's means we have to solve
2σ = 5
2 (17/√n) = 5
√n = 2 (17/5)
n = (34/5)² = 46.24
We better round up.
Answer: We need a sample size of 47 to be 95% certain of being within 5 points of the mean
