A boy lost 55% of his pocket money.if he had 67½kobo left,how much was his pocket money?

A radar gun was used to record the speed of a swimmer (in meters per second) during selected times in the first 2 seconds of a r

Natalka [10]

Trapezoidal is involving averageing the heights
the 4 intervals are
[0,4] and [4,7.2] and [7.2,8.6] and [8.6,9]

the area of each trapezoid is (v(t1)+v(t2))/2 times width

for the first interval
the average between 0 and 0.4 is 0.2
the width is 4
4(0.2)=0.8

2nd
average between 0.4 and 1 is 0.7
width is 3.2
3.2 times 0.7=2.24

3rd
average betwen 1.0 and 1.5 is 1.25
width is 1.4
1.4 times 1.25=1.75

4th
average betwen 1.5 and 2 is 1.75
width is 0.4
0.4 times 1.74=0.7

add them all up
0.8+2.24+1.75+0.7=5.49

5.49
t=time
v(t)=speed
so the area under the curve is distance
covered 5.49 meters

8 0

2 years ago

A manufacturing company produces valves in various sizes and shapes. One particular valve plate is supposed to have a tensile st

maxonik [38]

Answer:

$z=\frac{5.0611-5}{\frac{0.2803}{\sqrt{42}}}=1.413$

$p_v =2*P(z>1.413)=0.158$

If we compare the p value and the significance level given $\alpha=0.1$ we see that $p_v>\alpha$ so we can conclude that we have enough evidence to fail reject the null hypothesis, so we can't conclude that the average tensile strength is different from 5lbs/mm at 10% of signficance

Step-by-step explanation:

Data given and notation

$\bar X=5.0611$ represent the sample mean

$\sigma=0.2803$ represent the population standard deviation for the sample

$n=42$ sample size

$\mu_o =5$ represent the value that we want to test

$\alpha=0.1$ 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)

State the null and alternative hypotheses.

We need to conduct a hypothesis in order to check if the true mean is different from 5, the system of hypothesis would be:

Null hypothesis: $\mu = 5$

Alternative hypothesis: $\mu \neq 5$

If we analyze the size for the sample is > 30 but 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".

Calculate the statistic

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

$z=\frac{5.0611-5}{\frac{0.2803}{\sqrt{42}}}=1.413$

P-value

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

$p_v =2*P(z>1.413)=0.158$

Conclusion

If we compare the p value and the significance level given $\alpha=0.1$ we see that $p_v>\alpha$ so we can conclude that we have enough evidence to fail reject the null hypothesis, so we can't conclude that the average tensile strength is different from 5lbs/mm at 10% of signficance

8 0

2 years ago

3 kg of rump steak costs £42 Adel buys 4 kg of rump steak Work out how much Adel Pays

OLEGan [10]

Answer:

£56

Step-by-step explanation:

you first have to find out how much one kg is so you do 42/3=14

then times is by 4, 14x4=56

5 0

2 years ago

A 135-page notebook has 33 writing lines on each page. What is the total number of writing lines in the entire notebook? Enter y

lidiya [134]

Answer:

4,455 writing lines

Step-by-step explanation:

135 * 33= 4,455

hope this helps!!

7 0

2 years ago

Read 2 more answers

Julia went into a movie theater and bought 2 bags of popcorn and 5 pretzels, costing

andreyandreev [35.5K]

Answer:

A bag of pop corn costs $8, and each Pretzel costs $4.25.

Step-by-step explanation:

Let $b$ be the price of popcorn, and $p$ the price of Pretzels. If the girl bought 2 bags of popcorn and 5 Pretzels and it cost her $37.25, we have the equation

$2b+5p=37.25$ <em>(this says that the cost of 2 popcorn bags plus 5 pretzels equals $37.25)</em> .

And, since Zoe bought 8 popcorn bags and 9 Pretzels with a total price of $102.25, we get the equation

$8b+9p=102.25$ <em> (this says that the cost of 8 popcorn bags plus 9 Pretzels equals $102.25).</em>

Thus, we have two equations

1. $2b+5p=37.25$

2. $8b+9p=102.25$

and we solve them by first multiplying equation (1) by 4:

$4(2b+5p=37.25 )\rightarrow (8b+20p=149)$ ,

and then subtracting it from equation (2):

$\:\:\:\:\: 8b+9p=102.25\\-(8b+20p=149)\\\line(1,0){3 cm}\\-11p=-46.75\\\\\boxed{p=\$4.25}$

Now we put this value of $p$ into equation (1) and get:

$2b+5(4.25)=37.25$

and we solve for $b$ to get:

$2b=37.25-21.5$

$\boxed{ b=8}$

Therefore, a bag of popcorn costs $8, and each Pretzel costs $4.25.

8 0

2 years ago

A boy lost 55% of his pocket money.if he had 67½kobo left,how much was his pocket money?​

A boy lost 55% of his pocket money.if he had 67½kobo left,how much was his pocket money?