a. Ellie is saying that principle of conversion of units of time can be utilized to convert the number of minutes that Krystal spent on each activity to hours.

b. Krystal spent 7.33 hours or $7\frac{2}{6}$ hours on each activity.

Step-by-step explanation:

Time is any of the quantities of different measurements used to evaluate the duration of events. For example, if two men start a 100 metre race, it is time that is used to evaluate the duration of the first runner and the second runner. There are various units that are used in the measurement of time ranging from seconds to minutes to hours to days to weeks to months to years etc.

All the units for measuring time are interrelated and can be converted from one unit to the other. 60 seconds make a minute, 60 minutes make up an hour, 24 hours make up a day. Seven days = week, 4 weeks make a month and 12 months make a year.

a. In the question Ellie said that I can regroup the 440 minutes that Krystal spent on each activity as hours. What Ellie is virtually saying is that since all the units used in the measurement of time are interrelated for eg 7 days make a week and 4 weeks make a month, it is possible to change or convert time from one unit to another. This means that the 440 minutes that Krystal spent on each activity for eg reading books can be changed or transformed to another unit (hours).

b. Again, since Krystal spent 440 minutes on each activity, we can calculate how many hours Krystal spent on a single activity since we already know how many minutes that make an hour:-

Since 60 minutes make 1 hour, then the number of hours that Krystal spent on one activity is:

60 minutes ---------- 1 hour

440 minutes --------- ? hour

440/60 × 1

= 7.33 hours

= $7\frac{2}{6}$ hours

Therefore Krystal spent 7.33 hours or $7\frac{2}{6}$ hours on one activity

6 0

4 years ago

Renee scores an average of 153 points in a game of bowling, and her points in a game of bowling are normally distributed. Suppos

Lelu [443]

Answer:

$\sigma=\frac{175-153}{2}=11$

Step-by-step explanation:

Previous concepts

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".

Let X the random variable that represent points in a game of bowling of a population, and for this case we know the distribution for X is given by:

$X \sim N(153,unknown)$