Question

Plz help ASAP

Answer 1

the length of a spool of ribbon with a z-score of 0.7 is 92.3 cm

Step-by-step explanation:

Here we have , The lengths of spools of ribbon are normally distributed with a mean of 91.4 centimeters and a standard deviation of 1.3 centimeters.  What is the length of a spool of ribbon with a z-score of 0.7 . Let's find out:

According to Question we have following parameters as :

X = the length of a spool of ribbon

Mean(x) = 91.4 cm

standard deviation(y) = 1.3 cm

Z = 0.7

We know that Z score is given by :

⇒ $Z = \frac{X-Mean}{\Standrad deviation}$

⇒ $0.7 = \frac{X-91.4}{1.3}$

⇒ $0.91 = X-91.4$

⇒ $X=92.3cm$

Therefore , the length of a spool of ribbon with a z-score of 0.7 is 92.3 cm