Help me answer these questions please

A bakery sold 108 cupcakes in one day. The head baker predicted he would sell 88 cupcakes that day. What was the percent error o

tensa zangetsu [6.8K]

88/108 *100 = 81.48

100-81.48 = 18.52

I have heard this question before

7 0

3 years ago

1 point) According to one mathematical model, the average life expenctancy for American men born in 1900 was 55 years. Life expe

xxMikexx [17]

a)

Let t represents number of years after 1900

so that means for 1900, value of t is 0

We are given point as (0,55)

and it says that life expectancy increases by 0.2

so that means slope,m=0.2

equation of line is y=mt +b

or y=0.2t +b

now we use point (0,55)

55 =0.2(0) +b

55 =0+b

55= b

so b=55

plug it back into the equation,we get

y=0.2t +55

b)

We are given y=73

so we plug it into the equation we got in part a and solve for t

y=0.2t +55

73 =0.2t +55

73-55 =0.2t

18 =0.2t

18/0.2 =t

90 =t

so t=90

This means the birth year =1900+t =1900+90 =1990

5 0

3 years ago

It is advertised that the average braking distance for a small car traveling at 65 miles per hour equals 120 feet. A transportat

Mrrafil [7]

Answer:

State the null and alternative hypotheses.

We need to conduct a hypothesis in order to check if the mean is equal to 120 or not, the system of hypothesis would be:

Null hypothesis: $\mu = 120$

Alternative hypothesis: $\mu \neq 120$

Part 2

Calculate the statistic

We can replace in formula (1) the info given like this:

$z=\frac{114-120}{\frac{22}{\sqrt{36}}}=-1.636$

P-value

Since is a two sided test the p value would be:

$p_v =2*P(z$

Step-by-step explanation:

Data given and notation

$\bar X=114$ represent the sample mean

$\sigma=22$ represent the population standard deviation

$n=36$ sample size

$\mu_o =120$ represent the value that we want to test

$\alpha$ represent the significance level for the hypothesis test.

t would represent the statistic (variable of interest)

$p_v$ represent the p value for the test (variable of interest)

Part 1

State the null and alternative hypotheses.

We need to conduct a hypothesis in order to check if the mean is equal to 120 or not, the system of hypothesis would be:

Null hypothesis: $\mu = 120$

Alternative hypothesis: $\mu \neq 120$

If we analyze the size for the sample is > 30 and we know the population deviation so is better apply a z test to compare the actual mean to the reference value, and the statistic is given by:

$z=\frac{\bar X-\mu_o}{\frac{\sigma}{\sqrt{n}}}$ (1)

z-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".

Part 2

Calculate the statistic

We can replace in formula (1) the info given like this:

$z=\frac{114-120}{\frac{22}{\sqrt{36}}}=-1.636$

P-value

Since is a two sided test the p value would be:

$p_v =2*P(z$

8 0

3 years ago

What is the solution to the system of equations? x=4y 6 x-3y=4

ahrayia [7]

If you graph the two equations then you will find that they intersect at (-2,-2).

You then have to check your answer.

x=4y+6
(-2)=4(-2)+6
-2=-8+6
-2=-2

x-3y=4
(-2)-3(-2)=4
-2+6=4
4=4

8 0

3 years ago

Can you guys help me with this?

Ghella [55]

F(x)=2x^2-x-6
Factoring:
f(x)=2(2x^2-x-6)/2=(2^2x^2-2x-12)/2=[(2x)^2-(2x)-12]/2
f(x)=(2x-4)(2x+3)/2=(2x/2-4/2)(2x+3)→f(x)=(x-2)(2x+3)

g(x)=x^2-4
Factoring
g(x)=[sqrt(x^2)-sqrt(4)][sqrt(x^2)+sqrt(4)]
g(x)=(x-2)(x+2)

f(x)/g(x)=[(x-2)(2x+3)] / [(x-2)(x+2)
Simplifying:
f(x)/g(x)=(2x+3)/(x+2)

Answer: Third Option (2x+3)/(x+2)

7 0

4 years ago