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4 years ago

13

I need help this question I only need to pick 3

1 answer:

BARSIC [14]4 years ago

8 0

A. is 1
b. is 13
c. x= 2.549

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A half-century ago, the mean height of women in a particular country in their 20s was 64.7 inches. Assume that the heights of

Ainat [17]

Answer:

99.5% of all samples of 21 of today's women in their 20's have mean heights of at least 65.86 inches.

Step-by-step explanation:

We are given that a half-century ago, the mean height of women in a particular country in their 20's was 64.7 inches. Assume that the heights of today's women in their 20's are approximately normally distributed with a standard deviation of 2.07 inches.

Also, a samples of 21 of today's women in their 20's have been taken.

<u><em /></u>

<u><em>Let </em></u> $\bar X$ <u><em> = sample mean heights</em></u>

The z-score probability distribution for sample mean is given by;

Z = $\frac{\bar X -\mu}{\frac{\sigma}{\sqrt{n} } }$ ~ N(0,1)

where, $\mu$ = population mean height of women = 64.7 inches

$\sigma$ = standard deviation = 2.07 inches

The Z-score measures how many standard deviations the measure is away from the mean. After finding the Z-score, we look at the z-score table and find the p-value (area) associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X.

Now, Probability that the sample of 21 of today's women in their 20's have mean heights of at least 65.86 inches is given by = P( $\bar X$ $\geq$ 65.86 inches)

P( $\bar X$ $\geq$ 65.86 inches) = P( $\frac{\bar X -\mu}{\frac{\sigma}{\sqrt{n} } }$ $\geq$ $\frac{65.86-64.7}{\frac{2.07}{\sqrt{21} } }$ ) = P(Z $\geq$ -2.57) = P(Z $\leq$ 2.57)

= <u>0.99492 or 99.5%</u>

<em>The above probability is calculated by looking at the value of x = 2.57 in the z table which has an area of 0.99492.</em>

<em />

Therefore, 99.5% of all samples of 21 of today's women in their 20's have mean heights of at least 65.86 inches.

3 0

3 years ago

Match the proper noun to the common noun.

egoroff_w [7]

Uncle peter-relative

january-month

jesse owens-athlete

william shakespeare-author

sunday-day

chrysler-automobile

3 0

3 years ago

Read 2 more answers

For a school fundraiser mai will make school spirit bracelets. She will order bead wiring and alphabet beads to create the schoo

Andreas93 [3]

Answer:

235 bracelets

Step-by-step explanation:

Mai must spend $250 on wire and $5.30 per bracelet beads. Mai creates the expression.

We are given the equation:

5.3n+ 250 to represent the cost of making n bracelets.

The maximum number of bracelets Mai can make with a budget of $1500 Is calculated as:

$1500 = 5.3n+ 250

Collect like terms

1500 - 250 = 5.3n

1250 = 5.3n

n = 1250/5.3

n = 235.8490566 bracelets.

Bracelets are created as whole numbers and they can't be in decimal form.

Therefore, the maximum number of bracelets Mai can make with a budget of $1500 is 235 bracelets.

6 0

3 years ago

AB has endpoints at A(2,6) and B(6,8). What are the coordinates of the midpoint

Trava [24]

<em>The</em><em> </em><em>answer</em><em> </em><em>is</em><em> </em><em>(</em><em>4</em><em>,</em><em>7</em><em>)</em>

<em>look</em><em> </em><em>at</em><em> </em><em>the</em><em> </em><em>attached</em><em> </em><em>picture</em>

<em>Hope</em><em> </em><em>it</em><em> </em><em>helps</em><em>.</em><em>.</em>

<em>Good</em><em> </em><em>luck</em><em> </em><em>on</em><em> </em><em>your</em><em> </em><em>assignment</em>

6 0

3 years ago

In the pulley system shown in this figure, MQ = 30 mm, NP = 10 mm, and QP = 21 mm. Find MN.

ankoles [38]

<h2>Answer:</h2>

$\boxed{\overline{MN}=37.96}$

<h2>Step-by-step explanation:</h2>

For a better understanding of this problem, see the figure below. Our goal is to find $\overline{MN}$ . Since:

$\angle MRS=\angle MQP=90^{\circ} \\ \\ \overline{MQ}=\overline{MR}=30mm$

and $\overline{MN}$ is a common side both for ΔMRN and ΔMQN, then by SAS postulate, these two triangles are congruent and:

$\overline{RN}=\overline{QN}$

By Pythagorean theorem, for triangle NQP:

$\overline{QN}=\sqrt{\overline{NP}^2+\overline{QP}^2} \\ \\ \overline{QN}=\sqrt{10^2+21^2} \\ \\ \overline{QN}=\sqrt{541}$

Applying Pythagorean theorem again, but for triangle MQN:

$\overline{MN}=\sqrt{\overline{MQ}^2+\overline{QN}^2} \\ \\ \overline{MN}=\sqrt{30^2+(\sqrt{541})^2} \\ \\ \boxed{\overline{MN}=37.96}$

3 0

3 years ago