Answer:
您能再解釋一下嗎，謝謝
Step-by-step explanation:
<span>The rate is the ratio and the unit rate is the rate when the denominator is 1.
$279 for 9 tickets.
=> rate = $279 / 9 tickets => unit rate = $ 31/ ticket
$18 for 6 volleyballs.
=> rate = $ 18 / 6 volleyballs => unit rate = $ 3 / volleyball
4 fouls in 20 minutes.
=> rate = 4 fouls / 20 minutes => unit rate = 0.2 fouls / minute
36 strikeouts in 54 innings.
=> rate = 36 strikeouts / 54 innings => unit rate = 0.67 strikeouts / inning
</span>
Answer:
68% of pregnancies last between 250 and 282 days
Step-by-step explanation:
The Empirical Rule states that, for a normally distributed random variable:
68% of the measures are within 1 standard deviation of the mean.
95% of the measures are within 2 standard deviation of the mean.
99.7% of the measures are within 3 standard deviations of the mean.
In this problem, we have that:
Mean = 266
Standard deviation = 16
What percentage of pregnancies last between 250 and 282 days?
250 = 266 - 16
250 is one standard deviation below the mean
282 = 266 + 16
282 is one standard deviation above the mean
By the Empirical Rule, 68% of pregnancies last between 250 and 282 days
