Answer:
Approximately 104 joggers are female
Step-by-step explanation:
The U.S census bureau reported that 9 out of every 20 joggers at female.
Let x be the number of females out of 230 joggers.
Rewrite it as

Now we can write a proportion:

Cross multiply:
![20x=9\cdot 230\\ \\2x=9\cdot 23\ [\text{Divided by 10}]\\ \\x=\dfrac{9\cdot 23}{2}=\dfrac{207}{2}=103.5\approx 104](https://tex.z-dn.net/?f=20x%3D9%5Ccdot%20230%5C%5C%20%5C%5C2x%3D9%5Ccdot%2023%5C%20%5B%5Ctext%7BDivided%20by%2010%7D%5D%5C%5C%20%5C%5Cx%3D%5Cdfrac%7B9%5Ccdot%2023%7D%7B2%7D%3D%5Cdfrac%7B207%7D%7B2%7D%3D103.5%5Capprox%20104)
Answer: 0.86 of the exam scores are between 68 and 77.99 points
Step-by-step explanation:
Since the set of computer science exam scores are normally distributed, we would apply the formula for normal distribution which is expressed as
z = (x - µ)/σ
Where
x = computer science exam scores .
µ = mean score
σ = standard deviation
From the information given,
µ = 71.33 points
σ = 3 points
We want to find the proportion of the exam scores are between 68 and 77.99 points. It is expressed as
P(68 ≤ x ≤ 77.99)
For x = 68,
z = (68 - 71.33)/3 = - 1.11
Looking at the normal distribution table, the probability corresponding to the z score is 0.13
For x = 68,
z = (77.99 - 71.33)/3 = 2.22
Looking at the normal distribution table, the probability corresponding to the z score is 0.99
P(68 ≤ x ≤ 77.99) = 0.99 - 0.13 = 0.86
The problem is asking you to find x in this equation: 3×√x = x-4 I guessed and checked for this problem with numbers that were perfect squares like 4,9,16 etc. The number you are looking for is x=16 The square root of 16 is 4. 4x3=12 and 16-4 is 12.
Hope I helped!
3.8+7.6+9.3+31+43+54+62+89+107+119+123+127=775.7
775.7/12=64.64166666666667
So the mean is 64.64