I really don't understand i need help asap. They were asking to find f(-8)

Even though the population standard deviation is unknown, an investigator uses z rather than the more appropriate t to test a hy

Marta_Voda [28]

Answer:

a) The level of significance is large because here z is not appropriate.

b) The true critical value is larger than z because the level of significance is large.

Step-by-step explanation:

a) Based on the question under consideration, the true level of significance is larger than .05 level of significance is large, the reason being that z is not appropriate in this case.

b) The true critical value is larger than that of the critical z, this is because the level of significance is large.

t* in P(T > t*) = 0.975 is more than z* = 1.96 in P(z> z*) =0.975

3 0

3 years ago

A jet can fly at a rate of 480 mi/h in calm air. Traveling with the wind, the plane flew 1560 mi in the same amount of time it t

slamgirl [31]

Let the Rate of the Wind be : W mi/h

Given : The Jet can fly at a rate of 480 mi/h

⇒ Travelling with the Wind, Jet flies with a speed of (480 + W) mi/h

⇒ Travelling against the Wind, Jet flies with a speed of (480 - W) mi/h

Given : The Jet Travels 1560 Miles, Travelling with the Wind

<u>Let us calculate How much time the Jet takes to Travel 1560 Miles</u>

In One Hour : The Jet travels a Distance of (480 + W) Miles

⇒ The Jet travels a Distance of 1560 Miles in : $[\frac{1560}{480 + W}]\;Hours$

Given : The Jet Travels 1320 Miles, Travelling against the Wind

<u>Let us calculate How much time the Jet takes to Travel 1320 Miles</u>

In One Hour : The Jet travels a Distance of (480 - W) Miles

⇒ The Jet travels a Distance of 1320 Miles in : $[\frac{1320}{480 - W}]\;Hours$

Given : Time taken to fly 1560 Miles with the Wind = Time taken to fly 1320 Miles against the Wind.

⇒ $\frac{1560}{480 + W} = \frac{1320}{480 - W}$

⇒ 1560(480 - W) = 1320(480 + W)

⇒ (1560 × 480) - 1560W = (1320 × 480) + 1320W

⇒ 1560W + 1320W = (1560 × 480) - (1320 × 480)

⇒ 2880W = 480(240)

⇒ 288W = 48(240)

⇒ 72W = 12(240)

⇒ 6W = 240

⇒ W = 40

⇒ The Rate of Wind is 40 mi/h

5 0

3 years ago

There are 4 blood types, and not all are equally likely to be in blood banks. In a certain blood bank, 49% of

Ganezh [65]

Answer:

Step-by-step explanation:

they get 4% or 4 out of ever 100. that's 25 for one AB donation.

5 0

2 years ago

What is the length of the line segment in the x-y plane with end points at (-2,-2) and (2,3)?

diamong [38]

(-2-2)^2+(-2-3)^2=16+25=41 Length is square root of 41

5 0

3 years ago

A scientist has two solutions, which she had labeled solution A and solution B. each contains salt. she knows that solution A is

liq [111]

Answer:

$A +B = 40$ (1)

$A*0.65 + B*0.90 = 40*0.85$ (2)

From equation (1) we can solve for A and we got:

$A = 40 -B$ (3)

And replacing equation (3) into equation (2) we got:

$(40-B)*0.65 +0.9 B =34$

And solving the last equation for B we got:

$26 -0.65 B +0.9 B= 34$

$B = \frac{8}{0.25}= 32$

And solving for A from equation (3) we got:

$A = 40-32 = 8$

So then we need 8 ounces of solution A with concentration of 65% of salt and 32 ounces of solution B with 90% of salt

Step-by-step explanation:

Let A represent the amount of solution A and B the amount of solution B. We know that the concentration of A is 65% and the concentration for B is 90%.

We want to obtain a solution of 40 ounces with a concentration of 85% of salt.

Based on this we can set up the following equations:

$A +B = 40$ (1)

$A*0.65 + B*0.90 = 40*0.85$ (2)

From equation (1) we can solve for A and we got:

$A = 40 -B$ (3)

And replacing equation (3) into equation (2) we got:

$(40-B)*0.65 +0.9 B =34$

And solving the last equation for B we got:

$26 -0.65 B +0.9 B= 34$

We subtract in both sides 36:

$0.25 B =8$

And dividing both sides by 0.25 we got:

$B = \frac{8}{0.25}= 32$

And solving for A from equation (3) we got:

$A = 40-32 = 8$

So then we need 8 ounces of solution A with concentration of 65% of salt and 32 ounces of solution B with 90% of salt

4 0

3 years ago