A jet heads 60° north of east at 700 miles per hour. When the jet reaches a certain point, it encounters

The average expenditure on Valentine's Day was expected to be$100.89 (USA Today, February 13, 2006). Do male and femaleconsumers

stealth61 [152]

Answer:

(a) $62.16

(b) Male: $15.00

Female: $10.06

(c) Confidence Interval for male expenditure is ($106.40, $136.40)

Confidence interval for female expenditure is ($49.18, $69.30)

Step-by-step explanation:

(a) Male expenditure

Sample mean = $135.67, sd=$35, n=40, Z=2.576

Population mean = sample mean - (Z×sd)/√n = 135.67 - (2.576×35)/√40 = 135.67 - 14.27 = $121.40

Female expenditure

Sample mean= $68.64, sd=$20, n=30, Z=2.576

Population mean = 68.64 - (2.576×20)/√30 = 68.64 - 9.40 = $59.24

$121.40 - $59.24 = $62.16

(b) Male: Error margin = (t-value × sd)/√n

Degree of freedom = n-1 = 40-1= 39. t-value corresponding to 39 degrees of freedom and 99% confidence level is 2.708

Error margin = (2.708×35)/√40 = 94.78/6.32 = $15.00

Female

Degrees of freedom = n-1 = 30-1 = 29. t-value is 2.756

Error margin = (2.756×20)/√30 = 55.12/5.48 = $10.06

(c) Male

Confidence Interval (CI) = (mean + or - error margin)

CI = 121.4 + 15.00 = $136.40

CI = 121.4 - 15.00 = $106.40

Confidence Interval is ($106.40, $136.40)

Female

CI = 59.24 + 10.06 = $69.30

CI = 59.24 - 10.06 = $49.18

Confidence Interval is ($49.18, $69.30)

7 0

3 years ago

The circumference of super eight is four times the conference at Circle B which statement about the areas of the circle is true

ICE Princess25 [194]

When you have factors in shapes you must remember:
circumference and perimeter are in one unit measures
area is in squared units
volume is in cubed units

So, when the circumference of A is 4 times that of C there is a factor of 4.
Since we need to know the area the factor 4 will change to a factor of 4² since area is a squared unit.

The solution is 4²=16, the are of circle A is sixteen times the area of circle B.

4 0

3 years ago

Sally walked 3/4 of a mile before lunch and 1/2 of a mile after lunch. How far did she walk in all?

Wittaler [7]

Answer:

1 1/4

Step-by-step explanation:

5 0

3 years ago

Anybody got some answers?

kiruha [24]

I don’t know if this is right but this is what I figured.
37.245508982

4 0

3 years ago

Which choices are solutions to the following equations x^2+8x-2=18

Olin [163]

Answer:

-4 ± 2√6

Step-by-step explanation:

Rewritten in standard quadratic form, x^2+8x-2=18 becomes x^2 + 8x - 20 = 0.

Here the quadratic coefficients are a = 1, b = 8 and c = -20 and so the discriminant is b^2 - 4ac, or 8^2 - 4(1)(-20), or 96.

Because the discriminant is positive, we know that this quadratic has two different real roots. These roots are:

-b ± √(b² - 4ac)

x = -------------------------

2a

which in this case comes out to:

-8 ± √96 -8 ± 4√6

x = ------------------ = ------------------- = -4 ± 2√6

2 2

4 0

3 years ago