Approximately 99.7% of the data values will lie within 1 standard deviation on each side of the mean. is it true or false?

It is False.

the right answer is:

𝐀𝐩𝐩𝐫𝐨𝐱𝐢𝐦𝐚𝐭𝐞𝐥𝐲 𝟔𝟖% 𝐨𝐟 𝐭𝐡𝐞 𝐝𝐚𝐭𝐚 𝐯𝐚𝐥𝐮𝐞𝐬 𝐥𝐢𝐞 𝐰𝐢𝐭𝐡𝐢𝐧 𝟏 𝐬𝐭𝐚𝐧𝐝𝐚𝐫𝐝 𝐝𝐞𝐯𝐢𝐚𝐭𝐢𝐨𝐧 𝐨𝐟 𝐭𝐡𝐞 𝐦𝐞𝐚𝐧 𝐢𝐧 𝐛𝐨𝐭𝐡 𝐝𝐢𝐫𝐞𝐜𝐭𝐢𝐨𝐧𝐬.

Approximately 95% of the data values lie within 2 standard deviations of the mean in both directions.

Approximately 99.7% of the data values lie within 3 standard deviations of the mean in both directions.

Hope it helped