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2 years ago

14

Find the surface area of a square pyramid with side length 4 and slant height 5.

1 answer:

timofeeve [1]2 years ago

6 0

Answer:

56

Step-by-step explanation:

the surface area = (4×4) + (4×½×4×5)

= 16 + 40

= 56

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48% of the children in a summer camp are boys. If there are 1536 boys, how many children are there in the

pantera1 [17]

there are 3200 children in the summer camp.

Step-by-step explanation:

Percentage of boys in summer camp= 48%

No of boys in summer camp=1536 boys

Total number of children in summer camp= $\frac{1536}{48}*100\\ =3200$

So, there are 3200 children in the summer camp.

Keywords: Word Problems having Percentage

Learn more about word problems at:

#learnwithBrainly

3 0

2 years ago

The 2003 Statistical Abstract of the United States reported the percentage of people years of age and older who smoke. Suppose t

Paul [167]

Complete Question

The 2003 Statistical Abstract of the United States reported the percentage of people 18 years of age and older who smoke. Suppose that a study designed to collect new data on smokers and non smokers uses a preliminary estimate of the proportion who smoke of 0.30.

a. How large a sample should be taken to estimate the proportion of smokers in the population with a margin of error of 0.02? use 95% confidence.

b. Assume that the study uses your sample size recommendation in part (a) and finds 520 smokers. What is the point estimate of the proportion of smokers in the population?

c. What is the 95% confidence interval for the proportion of smokers in the population?

Answer:

a

$n = 2017$

b

$\^ p = 0.2578$

c

$0.238 < 0.278$

Step-by-step explanation:

Considering question a

From the question we are told that

The margin of error is $E = 0.02$

The preliminary estimate of the proportion who smoke is $p = 0.30$

From the question we are told the confidence level is 95% , hence the level of significance is

$\alpha = (100 - 95 ) \%$

=> $\alpha = 0.05$

Generally from the normal distribution table the critical value of $\frac{\alpha }{2}$ is

$Z_{\frac{\alpha }{2} } = 1.96$

Generally the sample size is mathematically represented as

$n = [ \frac{Z_{\frac{\alpha }{2} } }{E} ] ^2 * p(1 - p )$

=> $n = [ \frac{1.96 }{0.02} ] ^2 * 0.30(1 - 0.30 )$

=> $n = 2017$

Considering question b

From the question we are told that

The number of smokers is k = 520

Generally the point estimate of the proportion of smokers in the population is mathematically represented as

$\^ p = \frac{520 }{2017 }$

=> $\^ p = 0.2578$

Considering question c

Generally 95% confidence interval is mathematically represented as

$\^ p -E < p < \^ p +E$

=> $0.2578 - 0.02 < 0.2578 + 0.02$

=> $0.238 < 0.278$

7 0

2 years ago

You are remodeling your kitchen. You’ve contacted two tiling companies who gladly told you how long it took their workers to til

Papessa [141]

As given, let Jim's rate = x

Let Pete's rate =y

Jim completed half the floor in 12 hours so it's $12\times rate$ = 12x

Pete completed the other half of the floor in 10 hours so its $10\times rate$ =10y

As floor area is equal so,

$12x=10y$ .............(1)

Now, given is that Pete can lay 25 more tiles per hour than Jim, this gives=

$y=x+25$ ...... (2)

Putting the value of y from equation (2) in equation (1) , we get

$12x=10(x+25)$

So, the equation is : $12x=10(x+25)$

If you want to solve it, it becomes:

$12x=10x+250$

$2x=250$

$x=125$

Hence, Jim can lay 125 tiles and Pete can lay 25 more so 125+25=150 tiles.

4 0

2 years ago

Read 2 more answers

Filiz is walking at a bearing of 300°. When she has traveled 20 meters, how far west from her starting point is she? Round to th

ioda

She is 10m west of her starting point

4 0

2 years ago

Read 2 more answers

Find and explain the errors that were made in the following calculation of the coordinates of a midpoint. Then fix

nexus9112 [7]

Step-by-step explanation:

as shown in image provided

have a gd day :)

5 0

1 year ago