Pls help me with this

A solid shape is made by joining two cones.

dlinn [17]

The surface area of the solid shape is the amount of space on it

The radius of the two cones is 2.93 cm

<h3>How to determine the radius?</h3>

The given parameters are:

Cone 1: slant height, l = 2r
Cone 2: slant height, L = 3r
Surface area = 135. 21 cm²

The surface area of the shape is calculated using:

T = πr(L + l)

So, we have:

135.21 = πr(2r + 3r)

Evaluate

135.21 = 5πr²

Divide both sides by 5π

r² = 135.21/5π

Evaluate the quotient

r² = 8.61

Take the square root of both sides

r = 2.93

Hence, the radius of the cones is 2.93 cm

Read more about surface area at:

brainly.com/question/6613758

3 0

1 year ago

Suppose a consumer group suspects that the proportion of households that have three cell phones NOT known to be 30%. A cell phon

leva [86]

Answer:

We conclude that the actual percentage of households is equal to 30%.

Step-by-step explanation:

We are given that a consumer group suspects that the proportion of households that have three cell phones NOT known to be 30%.

Their marketing people survey 150 households with the result that 43 of the households have three cell phones.

Let p = proportion of households that have three cell phones NOT known.

So, Null Hypothesis, $H_0$ : p = 30% {means that the actual percentage of households is equal to 30%}

Alternate Hypothesis, $H_A$ : p $\neq$ 30% {means that the actual percentage of households different from 30%}

The test statistics that would be used here One-sample z-test for proportions;

T.S. = $\frac{\hat p-p}{\sqrt{\frac{p(1-p)}{n} } }$ ~ N(0,1)

where, $\hat p$ = sample proportion of households having three cell phones = $\frac{43}{150}$ = 0.29

n = sample of households = 150

So, the test statistics = $\frac{0.29-0.30}{\sqrt{\frac{0.30(1-0.30)}{150} } }$

= -0.27

The value of z test statistic is -0.27.

Also, P-value of the test statistics is given by;

P-value = P(Z < -0.27) = 1 - P(Z $\leq$ 0.27)

= 1 - 0.6064 = 0.3936

Now, at 1% significance level the z table gives critical value of -2.58 and 2.58 for two-tailed test.

Since our test statistic lies within the range of critical values of z, so we have insufficient evidence to reject our null hypothesis as it will not fall in the rejection region due to which we fail to reject our null hypothesis.

Therefore, we conclude that the actual percentage of households is equal to 30%.

4 0

2 years ago

If p - 5q = 4qr, p find the value of p when q = 4 and r = -1.

den301095 [7]

Answer:

p - 5q = 4qr where

q = 4 and r = -1 by applying these value

p - 5(4) = 4(4)(-1)

p - 20 = -16

p = -16 + 20

p = 4

4 0

1 year ago

Which ordered pair is a solution of the linear system: x+2y=-8 and

andrew-mc [135]

Answer:

option A

A(-2,-3)

Step-by-step explanation:

make y subject of formula

x+2y=-8

2y=-8-x

y=(-8-x)/2

y=-4-x/2

when x=-2

y=-4-(-2)/2

=-4-(-1)

=-4+1

=-3

(-2,-3) is an ordered pair

5 0

2 years ago

The price of a $250 item after successive discounts of 20% and 30% is?

Ivan

Answer:

The price of item after successive discounts are 20% and 30% is $140.

Step-by-step explanation:

The marked price of item is $250.

Two successive discounts are 20% and 30%.

Price of item after discounts of 20% is

$250-\frac{20}{100}(250)=250-50=200$

New price of item after first discount is $200.

Price of item after second discount, i.e., 30% is

$200-\frac{30}{100}(200)=200-60=140$

Therefore, the price of item after successive discounts are 20% and 30% is $140.

3 0

2 years ago